Matilda Simon, 3rd Baron Simon of Wythenshawe

Matilda Simon, 3rd Baroness Simon of Wythenshawe (born 10 April 1955) is a British peeress, retired academic, woodworker, and Green Party member. In 2002 she succeeded her father as the Baron Simon of Wythenshawe. In 2015 she came out as a transgender woman. Her claim to the barony, following her gender transition, was accepted by the Lord Chancellor in 2022, so she became the first transgender peer of the realm.

Early life, family, and education Lady Simon was born in 1955, the second child of The Honourable Roger Simon and Anthea Daphne Simon. She was assigned male at birth. Her father was a solicitor, political activist, and left-wing journalist who served as secretary of the Labour Research Department. In 1960, her father inherited the Simon barony of Wythenshawe upon the death of his father, Ernest Simon, 1st Baron Simon of Wythenshawe, who was elevated to the peerage in 1947 by George VI.

Simon was educated at St Paul's School, London, before attending Balliol College, Oxford between 1973 and 1977. At Oxford, she earned a first class degree in Engineering and won the Lubbock Prize for Engineering undergraduates. She was also a member of her college's Junior Common Room committee. In 2020, she wrote that she was "oddly proud of having been one of the first women at Balliol, even though nobody was aware of it."

Simon moved to University of Manchester's Engineering Department in 1979

In March 2014, she and her partner founded Rollins Wood, a 7-acre community woodland in Marple Bridge, planting 1,200 trees the following year.

Politics Simon joined the Green Party of England and Wales around the year of 2016. She stood as a Green candidate in the 2026 Stockport Metropolitan Borough Council election. Contesting for a seat in the Bredbury Green & Romiley ward, she came third with 475 votes (10.3%) and was not elected; the seat was eventually won by the Liberal Democrat candidate.

Peerage As Lady Simon was assigned male at birth, later coming out as a transgender woman in 2015, she inherited the Simon barony of Wythenshawe in 2002 after the death of her father, which only passes to the heirs male of the body of the first Baron. Her claim to the peerage was approved by the Lord Chancellor, Dominic Raab, in 2022 after she had changed her gender identity. According to the Gender Recognition Act 2004, a person changing gender does not affect the descent of any peerage or dignity or title of honour. In 2022, she successfully applied to be added to the "Register of Hereditary Peers", the list of "eligible hereditary peers who have indicated their wish to stand in by-elections for the House".

The Daily Telegraph suggested she could stand in the by-election for the House of Lords in 2023 to replace Lucius Cary, 15th Viscount Falkland, but she did not do so. (Cary had been elected to the House as a Liberal Democrat in 1999, but switched to Crossbencher in 2011. By convention, he would be replaced by a Liberal Democrat, but peers from any party were allowed to stand for the by-election.) Had she succeeded Lord Falkland, she would have been the first transgender woman to join the House of Lords as one of the ninety-two hereditary peers. She would have become the first woman with a hereditary peerage to sit in the House of Lords since the retirement of Margaret of Mar, 31st Countess of Mar and the second transgender person in Parliament, after Katie Wallis.

Most British peerages (including the Simon barony) can only be inherited by men under the system of agnatic primogeniture. No female hereditary peers have entered the House of Lords through the by-election process yet, Conservative politician Anne Jenkin, Baroness Jenkin of Kennington, and Charlotte Carew Pole both called into question the validity of Lady Simon's peerage, it would have passed to a male-line cousin of Margaret and Matilda instead.

Personal life According to her entry in Who's Who, Simon was married to Sally Mitchell from 1987 until her death in 2014; she has two daughters. She has volunteered with the British charity Diversity Role Models.