Mayer started her career at The Economist and has worked as a foreign correspondent at the German news weekly Focus. Mayer was president of the Foreign Press Association in London from June 2003 until June 2005. She worked at Time from 2004 to April 2015, serving as Time's Editor at Large, Europe Editor, London Bureau Chief and Senior Editor. Mayer began legal action against Time in July 2017 on the grounds of age and gender discrimination. Her attorney was Dr. Ann Olivarius, a founding member of the Women's Equality Party, which was co-founded by Mayer ; Mayer and Olivarius were featured in a 2018 of Thomson Reuters Legal UK & Ireland’s podcast series, "The Hearing." Mayer's lawsuit prompted other journalists to seek legal advice about sexual discrimination and ended with an "amicable resolution" in 2018. In 2011 Mayer wrote Amortality: The Pleasures and Perils of Living Agelessly about the pros and cons of people living longer. Her 2015 biography of Prince Charles, published as, Charles: The Heart of a King, published in the US as Born to Be King, generated worldwide headlines with its claims of dysfunction in the royal courts. Clarence House, which had facilitated access to the Prince, distanced itself from the book. Mayer stood by the content. The book was a Sunday Times Top Ten bestseller. Mayer's non-fiction, Attack of the 50ft. Women, was published in 2017. The book covers the benefits of gender equality and how it is being promoted in various countries, and has been described as "a compelling feminist call to arms".
Women's Equality Party
Mayer co-founded the Women's Equality Party with Sandi Toksvig in March 2015 and is its President. The party has core objectives: equal representation, equal pay, equality in and through the media, equal education, equal health, shared opportunities in parenting and caregiving and an end to violence against women; its first policy commitments were launched by the party's first leader, Sophie Walker, at Conway Hall on 20 October 2015. In February 2018 Mayer stated: "The party also welcomed all genders. Everyone is born with a sex, usually, though not always, male or female. Gender is the product of social and cultural factors that can be changed. The very first policy document made clear that WE supported “the right of all to define their sex or gender or to reject gendered divisions as they choose." The party won its first seat in the local elections in May 2019. Mayer stood as the lead candidate for the party in the 2019 European Elections in London.
Primadonna Festival
Mayer co-founded the Primadonna Festival in 2019, a festival of ideas, writing, music and comedy at Laffitt's Hall in Pettaugh, Suffolk, aiming to give prominence to women and to new voices.
