Aileen is recommended by the directories as a leading silk in administrative & public law, education law, civil liberties & human rights, employment law and independent investigations. She has particular interests in discrimination/equality and human rights law, including the law relating to information/ freedom of expression, and extensive experience in conducting independent investigations for a variety of bodies including FTSE 100 and multinational companies, local authorities and national charities, law firms, political parties, religious organisations and universities.

Aileen’s interests in human rights and discrimination law have been reflected in litigation and investigations concerning the boundaries between free speech and alleged antisemitism and transphobia as well as between religious freedom and anti- discrimination rights. She has extensive experience on advising in relation to trans-related issues in the context of education, employment and policing. Recent cases include XTX v Mazars (successful defence against allegations of race discrimination in the context of sanctions) and Newman v Metropolitan Police (successful defence against allegations of discrimination based on gender critical beliefs). Aileen has also advised many organisations on the investigation and management of complaints of sexual harassment/ assault and harassment/ bullying, including at the highest levels.

Aileen is recommended by Chambers & Partners (2026) as ‘incredibly approachable and client-focused’, combining ‘great communication skills with pre-eminent expertise of her specialism’, ‘absolutely top class’; ‘very articulate and unshowy’ and ‘brilliant academically’. Legal 500 (2026) praises her ‘razor sharp intellect’ and ‘brilliant’ ‘ability to assimilate vast amounts of information’. Previous editions have praised her as ‘very responsive and very good with clients… tactically astute and able to cut through large quantities of information and provide clear, strategic and commercial advice quickly’; ‘really able to think outside of the box’’; ‘exceptional in every aspect of advice and client relationships… a true expert’ (Chambers and Partners 2024); ‘an expert on discrimination law’ whose ‘no- nonsense approach gives confidence to the client’ (Legal 500, 2024), ‘a top-class practitioner’, ‘an excellent KC and a pleasure to work with’  and ‘a leading lawyer [whose] understanding of the key issues and fundamental principles really sets her apart’ (Legal 500 2023); ‘a fierce advocate’ who ‘distils complicated issues into manageable areas … has a phenomenal ability to cut through swathes of information to get to the heart of the matter and has a genuine partnership approach’ (Legal 500, 2022), and as having a ‘stellar academic background [which] means that she is totally on top of the law, and [who] draws on that fountain of knowledge to provide comprehensive but commercial advice’ (Chambers & Partners 2022).

Aileen has a distinguished history as an academic and is internationally recognised as a leading academic in discrimination, equality and human rights law. Her academic work has been cited in the ECHR and the domestic courts. She is the former Chair of the Human Rights Lawyers Association (2019-2021); a current or former member of the editorial committees of Public Law, European Human Rights Law Review, International Journal of Discrimination and the Law and Education Law Reports and former Executive Committee Member of the Industrial Law Society. She has been trustee of the British Institute of Human Rights and was until 2016 the UK’s National Expert on the European Networks of Legal Experts in the Field of Gender Equality and of Experts in the Non-discrimination Field. She has published very widely on human rights, discrimination and employment law.

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  • Quotation symbolAileen is exceptional in every aspect of advice and client relationships. She is a true expert.

    Quotation symbolChambers & Partners 2024

  • Quotation symbolAileen McColgan’s stellar academic background means that she is totally on top of the law, and she draws on that fountain of knowledge to provide comprehensive but commercial advice.

    Quotation symbolChambers & Partners 2022

  • Quotation symbolAileen is an absolute star. She is quick to understand issues and to provide advice in a succinct and clear manner. She has an ability to break down legal language and to address matters in a manner that is easily understandable.

    Quotation symbolLegal 500 2021

Expertise

ToggleEducation Law (non-university)

Aileen has extensive experience in advising and representing universities as well as in litigation and advisory work relating to schools and local authoritiesʼ education-related functions. Her background as an academic gives her a particular insight into disputes arising in the context of higher education. She has appeared in many higher education judicial review challenges for universities as well as for the Office of the Independent Adjudicator; has undertaken investigations for universities including in relation to sexual harassment and antisemitism complaints; has represented universities in employment-related and other claims brought by academics; and has acted for academics in internal disciplinary procedures relating to allegations of antisemitism and harassment. Aileen recently represented the University of Bristol in University of Bristol v Abrahart [2024] EWHC 299 (KB), which concerned the duties of universities under the Equality Act 2010 and common law. She has also represented schools and local authorities in cases arising in connection with trans pupils and students (see eg R (AI) v LB Wandsworth [2023] EWHC 2088 (Admin) and R(AB) v A County Council & Anor [2022] EWHC 2707 (Admin)) and also advised numerous organisations, including local authorities, on policies and guidance relating to trans children in schools. She has acted in cases concerning the termination of academy funding and appeared for Southall Black Sisters and Inspire in the Court of Appeal in HM Inspector of Education, Childrenʼs Services & Skills v Al-Hijraj School [2017] EWCA Civ 1426, [2018] 1 WLR 1471, a challenge to sex segregation in schools. Aileen was editor of the Education Law Reports until 2020 and argued the first successful challenge by a school to a local authority decision to name it in an EHC Plan (R (An Academy Trust) v Medway Council [2019] EWHC 156 (Admin).

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  • Aileen is absolutely top class!

    Chambers & Partners

  • She instantly cut to the heart of our matter and demonstrated her expertise and judgement in a way that reassured and strengthened the client.

    Chambers & Partners

  • Aileen is incredibly approachable and client-focused. She combines great communication skills with pre-eminent expertise of her specialism.

    Chambers & Partners

Download Education Law (non-university) CV

ToggleEmployment

Aileen has expertise across the range of employment law and is regularly instructed in high-value discrimination and whistleblowing cases for both claimants and respondents. She has considerable experience in appellate and High Court employment work including in relation to the enforcement of confidentiality and related obligations and a particular interest in cases relating to the balance between trans rights and rights relating to discrimination and freedom of expression.

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  • Aileen has provided excellent, detailed advice about complex legal issues and robust advice on strategy. Aileen's approach has been calm and measured, which has been of huge assistance.

    Chambers & Partners

  • Aileen McColgan is a very articulate and unshowy barrister. She is very effective.

    Chambers & Partners

  1. Newman v Commissioner of Police of the Metropolis

    2305069/2023, 25 June 2025

    Aileen represented the Met Police in a successful defence to a claim of discrimination on grounds of gender critical beliefs.

Download Employment CV

ToggleHuman Rights / Civil Liberties / Discrimination

Aileen has extensive experience across the range of civil liberties/ human rights challenges including discrimination claims (XTX v Mazars (2025), in which the County Court rejected a race discrimination claim on grounds of Russian nationality arising in connection with the sanctions regime); claims relating to freedom of expression (Forstater v CGD Europe Ltd [2022] ICR 1 and privacy law (Fearn & Ors v Board of Trustees of the Tate Gallery [2023] UKSC 4, [2023] 2 WLR 339. She has a particular interest in the balance between competing non-discrimination rights. Aileen provides advice in relation to discrimination/ equality matters to a range of organisations from police forces and regulatory bodies to schools and charities.

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  • Aileen is thoughtful with quick turnaround at a high quality.

    Chambers & Partners

  • Aileen is very personable and easy to work alongside.

    Chambers & Partners

  1. University of Bristol v Abrahart

    [2024] EWHC 299 (KB)

    Aileen represented the University in an appeal from findings of disability discrimination arising from the suicide of a student

  2. XTX v Mazars

    KA-2026-000003

    Aileen successfully defended the respondent against claims of race discrimination arising in connection with the Russians sanctions regime

  3. Fearn & Ors v Board of Trustees of the Tate Gallery

    [2023] UKSC 4, [2023] 2 WLR 339

    Aileen appeared for the Tate in this case which concerned nuisance and human rights.

  4. Forstater v CGD Europe & Ors

    [2021] IRLR 706 (EAT)

    Aileen appeared for Index on Censorship in this case which established that gender critical feminism was a protected belief for the purposes of the Equality Act 2010.

Download Human Rights / Civil Liberties / Discrimination CV

ToggleInformation and Data Protection

Aileen has been instructed in a number of freedom of information and data protection claims including claims involving the Cabinet Office and the Ministry of Defence. She has acted in a significant number of protection from harassment claims which concerned the balance between freedom of expression and harassment. Aileen has provided extensive advice on data protection and privacy matters arising in connection with the publication of reports dealing with child sexual exploitation/ abuse, on questions of data protection arising in connection with disclosure within the context of litigation and on data protection and related issues arising in connection with gender reassignment.

  1. Ward & Ors v McGovern

    HQ18M0026 (2019, High Court)

    Aileen secured injunctive relief for the claimant under the Protection from Harassment Act in which freedom of expression was in issue

  2. Big Brother Watch & Ors v UK

    [2018] ECHR 58170/13 (ECtHR)

    Aileen represented the EHRC in a challenge to state surveillance

  3. Big Brother Watch & Ors v UK

    [2018] ECHR 58170/13 (ECtHR)

    Aileen represented the EHRC in a challenge to state surveillance

  4. Cabinet Office v Information Commissioner & Ashton

     [2018] UKUT 208 (AAC)

    Aileen represented the claimant in a successful defence of a FTT’s disclosure order

  5. Cabinet Office v Information Commissioner & Ashton

    [2018] UKUT 208 (AAC)

    Aileen represented the claimant in a successful defence of a FTT’s disclosure order

Download Information, Technology & Media CV

ToggleInvestigations and Inquiries

Aileen has an extensive investigations practice across a wide range of organisations and subject areas. She recently completed a major investigation for Brighton & Hove City Council into allegations of widespread harassment and bullying. She has conducted investigations into CEOs and Chairs of FTSE organisations and partners in law firms. Her investigations have spanned sectors from financial and legal services through higher education to local authority waste services. Aileen was Junior Counsel to the Independent Inquiry on Child Sexual Abuse during 2015-2016, and in that capacity led the investigations into the Anglican and Roman Catholic Churches. She also worked on the EHRCʼs Formal Investigation into the BBCʼs pay practices.

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  • Aileen did a great job. She was responsive and thoughtful in her approach.

    Chambers & Partners

  • Aileen's advice was always clear, pragmatic and timely, often delivered to challenging deadlines. Her client care was excellent.

    Chambers & Partners

Download Investigations and Inquiries CV

ToggleProfessional Discipline & Regulatory

Aileen is regularly instructed by professional regulatory bodies including the BSB and GMC and has acted for individuals facing regulatory action.

Download Professional Discipline & Regulatory CV

TogglePublic

Aileenʼs public law practice encompasses (in addition to education-related cases) every kind of public law from challenges by commercial bodies against public authority decision- making through social care challenges to PSED/ Article 14/ HRA discrimination claims and judicial reviews by and against police forces as well as election law. Aileen is regularly instructed by Arts Council England in connection with a range of matters including challenges to grant-related decision-making.

Until 2022 Aileen was on the editorial committee of Public Law.

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  • She is able to quickly get to grips with the issues in the case and what is key for her client. Aileen has a real measured and proportionate approach to her work.

    Chambers & Partners

  • Aileen is brilliant academically.

    Chambers & Partners

  1. R (AI) v Wandsworth LBC

    [2023] EWHC 2088 (Admin)

    Aileen successfully defended the local authority on a PSED challenge to its delivery of SEND education to trans children and young people.

  2. R (AB) v A County Council & Anor

    [2022] EWHC 2707

    Aileen represented the local authority in a successful defence to a challenge by a teacher to its treatment of a trans child.

Download Public CV

Achievements

ToggleBooks

Labour Law, with Hugh Collins and Keith Ewing (multiple editions currently CUP, 2025)

Discrimination Law: Text, Cases and Materials (multiple editions, currently Bloomsbury, 2024)

Special Educational Needs and Disability Discrimination in Schools (LAG, 2017) with Sarah Hannett and Elizabeth Prochaska

Discrimination, Equality and the Law (Hart: 2014)

Discrimination Law Handbook(ed.), (LAG, 2005 and 2002)

Women under the Law; the False Promise of Human Rights (Essex: Longman, 1999)

Equal Pay: Just Wages For Women (Clarendon Press, 1997)

The Case For Taking the ‘Dateʼ out of Rape (London: Pandora, 1996)

ToggleSelected Articles / Chapters in Books

Labour Law, with Hugh Collins and Keith Ewing (multiple editions currently CUP, 2025)

Discrimination Law: Text, Cases and Materials (multiple editions, currently Bloomsbury, 2024)

Special Educational Needs and Disability Discrimination in Schools (LAG, 2017) with Sarah Hannett and Elizabeth Prochaska

Discrimination, Equality and the Law (Hart: 2014)

Discrimination Law Handbook(ed.), (LAG, 2005 and 2002)

Women under the Law; the False Promise of Human Rights (Essex: Longman, 1999)

Equal Pay: Just Wages For Women (Clarendon Press, 1997)

The Case For Taking the ‘Dateʼ out of Rape (London: Pandora, 1996)

Insights&News

  1. News

    Aileen McColgan successfully defends the Met in gender critical belief judgment

    View News

  2. News

    11KBW shortlisted for 14 Awards at the Legal 500 UK Bar Awards 2025

    View News

  3. News

    11KBW shortlisted for 16 Awards at the Legal 500 UK Bar Awards 2024

    View News

  4. News

    Richard Leiper KC and Aileen McColgan KC speaking at 5th IFSEA International Conference on Executive & Founder Issues

    View News

  5. News

    8 Members of 11KBW appointed to the EHRC’s Panel of Counsel

    View News

  6. News

    Aileen McColgan KC writes Thomson Reuters’ practice note on ‘Transgender pupils in schools’

    View News

  7. Podcasts

    Andrew Smith and Aileen McColgan KC on words used in the heat of the moment

    View Podcasts

  8. News

    Aileen McColgan KC represents the Appellant in University of Bristol v Dr Robert Abrahart

    View News

View more →

  • Quotation symbol

    ‘razor sharp intellect’ ‘brilliant… ability to assimilate vast amounts of information’.

    Legal 500 (2026)

  • Quotation symbol

    Incredibly approachable and client-focused’, ‘great communication skills’ ‘pre-eminent expertise of her specialism’, ‘absolutely top class’; ‘very articulate and unshowy’ and ‘brilliant academically’.

    Chambers & Partners (2026)

  • Quotation symbol

    Great communication skills

    Chambers & Partners 2026

  • Quotation symbol

    Absolutely top class

    Chambers & Partners 2026

  • Quotation symbol

    Very articulate and unshowy

    Chambers & Partners 2026

  • Quotation symbol

    Brilliant academically

    Chambers & Partners 2026

  • Quotation symbol

    Razor sharp intellect

    Legal 500 2026

  • Quotation symbol

    Brilliant… ability to assimilate vast amounts of information

    Legal 500 2026

  • Quotation symbol

    Incredibly approachable and client-focused

    Chambers & Partners 2026

  • Quotation symbol

    I entirely trust Aileen to deliver

    Chambers & Partners 2024

  • Quotation symbol

    Aileen is exceptional in every aspect of advice and client relationships. She is a true expert

    Chambers & Partners 2024

  • Quotation symbol

    She is able to think outside of the box, coming up with solutions and providing advice in a way clients want to see

    Chambers & Partners 2024

  • Quotation symbol

    Aileen combines encyclopedic knowledge of the relevant case law and sophisticated understanding of the issues. Her advice was invaluable in finding pragmatic ways forward

    Chambers & Partners 2024

  • Quotation symbol

    Aileen is very responsive and very good with clients. She is tactically astute and able to cut through large quantities of information and provide clear, strategic and commercial advice quickly

    Chambers & Partners 2024

  • Quotation symbol

    A great advocate to have in your corner who knows what to say, when to say it and more importantly how little to say when required

    Chambers & Partners 2024

  • Quotation symbol

    Aileen has an encyclopaedic knowledge and really in-depth understanding of the law of equality and discrimination as applicable to schools

    Legal 500 2024

  • Quotation symbol

    An expert on discrimination law, and her no- nonsense approach gives confidence to the client

    Legal 500 2024

  • Quotation symbol

    Very responsive, approachable and strong with the clients

    Chambers & Partners 2024

  • Quotation symbol

    Aileen is knowledgeable and really able to think outside of the box. She often comes up with solutions and provides advice in a way clients want to see it

    Chambers & Partners 2024

  • Quotation symbol

    She is absolutely strong in education and has an extremely good understanding of the principles and underlying issues

    Chambers & Partners 2024

  • Quotation symbol

    ‘an expert on discrimination law’ whose ‘no- nonsense approach gives confidence to the client’

    Legal 500 (2024)

  • Quotation symbol

    ‘very responsive and very good with clients… tactically astute and able to cut through large quantities of information and provide clear, strategic and commercial advice quickly’; ‘rely able to think outside of the box’’; ‘exceptional in every aspect of advice and client relationships… a true expert’

    Chambers & Partners (2024)

  • Quotation symbol

    Aileen is very effective in bringing all the knowledge she has to the fore in a case

    Chambers & Partners 2023

  • Quotation symbol

    Aileen is a leading lawyer. Her understanding of the key issues and fundamental principles really sets her apart.

    Legal 500 2023

  • Quotation symbol

    Aileen is very passionate about what she does.

    Chambers & Partners 2023

  • Quotation symbol

    She is an excellent KC and a pleasure to work with

    Chambers & Partners 2023

  • Quotation symbol

    Aileen is a top-class practitioner

    Chambers & Partners 2023

  • Quotation symbol

    ‘a top-class practitioner’, ‘an excellent KC and a pleasure to work with’ and ‘a leading lawyer [whose] understanding of the key issues and fundamental principles really sets her apart’

    (Legal 500, 2023)

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    Fierce advocate, readily available and approachable to speak about issues as they arise

    Legal 500 2022

  • Quotation symbol

    Aileen is able to pick up the matter, and the factual and legal detail, very quickly at the last minute before the final hearing, and does a good job of cross-examining claimants

    Legal 500 2022

  • Quotation symbol

    She knows an awful lot about universities

    Legal 500 2022

  • Quotation symbol

    She distils complicated issues into manageable areas. She has a phenomenal ability to cut through swathes of information to get to the heart of the matter and has a genuine partnership approach

    Legal 500 2022

  • Quotation symbol

    She is easy to engage with and provides high-quality, commercial and sensible advice

    Chambers & Partners 2022

  • Quotation symbol

    Aileen McColgan’s stellar academic background means that she is totally on top of the law, and she draws on that fountain of knowledge to provide comprehensive but commercial advice

    Chambers & Partners 2022

  • Quotation symbol

    She really knows discrimination law and she is very effective in cases in that area

    Chambers & Partners 2022

  • Quotation symbol

    She goes that extra mile for her clients

    Chambers & Partners 2022

  • Quotation symbol

    She is accessible and provides clear and robust advice on a timely basis

    Chambers & Partners 2022

  • Quotation symbol

    ‘stellar academic background [which] means that she is totally on top of the law, and [who] draws on that fountain of knowledge to provide comprehensive but commercial advice’

    Chambers & Partners 2022

  • Quotation symbol

    ‘a fierce advocate’ who ‘distils complicated issues into manageable areas … has a phenomenal ability to cut through swathes of information to get to the heart of the matter and has a genuine partnership approach’

    Legal 500, 2022

  • Quotation symbol

    Aileen is an absolute star. She is quick to understand issues and to provide advice in a succinct and clear manner. She has an ability to break down legal language and to address matters in a manner that is easily understandable

    Legal 500 2021

  • Quotation symbol

    Her work on complex pleadings has been exceptionally good

    Legal 500 2021

  • Quotation symbol

    Works extremely hard for her clients and her advice is always commercial

    Legal 500 2021

  • Quotation symbol

    A highly accomplished barrister with an impressive performance in both written advice and advocacy skills

    Legal 500 2021