About McO

International civil litigators with offices in the UK and US.

Our purpose is to make whole those who have suffered injustice.
Our vision is a better world where the law works for everyone.

About Us

We want our clients to succeed. What “success” means in practice depends on their needs and goals. The law can be a wonderful thing: a framework allowing people to work together productively, or resolve furious disagreements, or right deeply felt wrongs. It can also be slow, expensive, inconclusive, vexing, even perverse. Recognizing the law’s limitations, as well as its power, helps us give smart advice tailored to helping our clients achieve the success they seek.

Part of why we take this approach stems from our history. Dr. Ann Olivarius started the firm in 1996, but she already had substantial experience in the law, both as lawyer, and, very usefully, as litigant.

Firm History

Before she even went to law school, when she was just 22 years old, Olivarius helped make American legal history as a plaintiff in the landmark 1977 Title IX case Alexander v. Yale, which for the first time determined that US universities were illegally discriminating against women students if they did not have a system for deterring and punishing sexual harassment by professors. For Olivarius, the experience of fighting for equality in a courtroom proved galvanizing, and she decided to pursue a legal career. After obtaining experience as an investment banker, business consultant, private firm lawyer and foundation executive, she founded McAllister Olivarius in 1996, concentrating on helping people who have been treated unfairly. Our firm has grown steadily since.

Others have joined Olivarius in the firm’s leadership, adding their own experience to our Executive Committee. Dr. Jef McAllister, Managing Partner, joined full-time in 2007, having consulted for the firm since it began. McAllister previously worked for Sidley Austin in New York and clerked for Chief Judge Robert F. Peckham of the U.S. District Court in San Francisco. He joined us from TIME Magazine, where he had been London Bureau Chief for eight years, and before that TIME’s White House Correspondent and Diplomatic Correspondent in Washington. His knowledge of global politics and leaders adds an extra dimension of service to our clients. Georgina Calvert-Lee, Senior Litigation Counsel and head of our UK practice, is an English barrister with extensive legal experience in the United States, and contributes to our expertise in transatlantic transactions and litigation.

A British-American law firm with high standards

We have built an international reputation for providing skillful and supportive representation to people unfairly treated by employers, universities, online harassers, government bodies and others. We’ve represented many victims of sexual harassment and discrimination at major institutions, including Amazon, Oxford, Cambridge, Deutsche Bank, the University of California, the University of Rochester, TIME Magazine, the Catholic Church, Jehovah’s Witnesses, Mount Sinai Health System and other major banks, law firms and companies. We’ve taken on some of the world’s most powerful, sophisticated and legally aggressive institutions, successfully; and are glad to be able to offer our accumulated experience in the service of others who have been wronged.

Photo of a lawyers' meeting at McAllister Olivarius Maidenhead office.
A lawyers’ meeting at McAllister Olivarius’ Pearce Building office.
Photo of Chrissy Chambers and Bria Kam outside the Royal Courts of Justice with Ann Olivarius.
Chrissy Chambers and Dr Olivarius address the press outside the Royal Courts of Justice after winning the landmark revenge porn ruling.
Photo of Jef McAllister appearing on BBC Dateline London
A former White House correspondent, Dr. McAllister regularly appears on BBC TV and radio, Sky News and other outlets.
Photo of Dr McAllister chairing a panel at the World Economic Forum 2003, with future US President Biden.
Dr Jef McAllister chairing a panel at the World Economic Forum 2003, with future US President Biden.
photo of Georgina Calvert-Lee speaking on-stage at a conference.
Georgina Calvert-Lee, Head of our UK practice, regularly speaks about universities’ responsibility to handle sexual misconduct complaints.
photo of McAllister Olivarius and The 1752 Group's Sector Guidance.
The 1752 Group and McAllister Olivarius Sector Guidance to Address Staff Sexual Misconduct in UK Higher Education.
Dr Olivarius photographed with Anita Hill and Catherine Lhamon, fellow recipients of YaleWomen’s Lifetime Achievement Award.
Dr. Olivarius, pictured here with Anita Hill and Catherine Lhamon, fellow recipients of YaleWomen’s Lifetime Achievement Award.
Photo of Dr Olivarius speaking on the topic of revenge porn at TEDxReading
Dr Ann Olivarius at TEDxReading – ‘Revenge Porn: The Naked Truth’.
photo of group of people walking into Oxford County Court.
Georgina Calvert-Lee and Honza Cervenka walking into court with our clients, Reena and Sandeep Mander. The couple later won their landmark adoption-discrimination case.
photo of Phil Davis sitting with presenter Jon Snow.
Phil Davis, Chief of Staff, photographed with Channel 4’s Jon Snow in Tanzania. The two were filmed as part of a Channel 4 TV news report on Malaria in Africa.

I will always be grateful for your unwavering support of me. Equally, I will always be grateful for showing me how to find my voice and strength.

Title IX case against UCLA, client confidential

It was such a weight off our shoulders; suddenly somebody else with a lot more experience was managing the case.

Sandeep Mander, Mander v. Royal Borough of Windsor & Maidenhead

We really thought that there was nothing that anybody could do for us. We were wrong.

Dr Celeste Kidd, Aslin et al v. University of Rochester et al

To get the result you got you must be as tough with your legal opposites as you are kind and understanding to your clients.

AOA client, confidential

Compared with other law firms I’ve worked with, no one matches the combination that McO has of experience, brilliance, ferocious fighting and deep empathy for their clients.

Dr Holly Atkinson, Atkinson et al v. Mount Sinai Health System, Inc. et al

Because my case could not bear public scrutiny, a very powerful institution used massive financial resources to try to crush me for asking for my disability rights. This was a huge mistake, as they didn’t know that I would obtain McO representation. I couldn’t ask for better representation.

Disability Rights client, confidential

I would like to say from bottom of my heart, thank you. Thank you to all the team. Now I can go and forget my former employer. God bless you all.

Unfair Dismissal client, confidential