Ray Strachey (born Rachel Pearsall Conn Costelloe; 4 June 1887 – 16 July 1940) was a British feminist politician, mathematician, engineer, artist and writer.
Her father was Irish barrister Benjamin “Frank” Conn Costelloe, and her mother was art historian Mary Berenson. She was the elder of the two girls in her family. Her younger sister was Karin Stephen, née Costelloe, who married Adrian Stephen, Virginia Woolf’s younger brother, in 1914. Ray was educated at Kensington high school and at Newnham College, Cambridge, where she achieved third class in part one of the mathematical tripos (1908).
Like some other female Mathematics graduates of the time, such as Margaret Dorothea Rowbotham and Margaret Partridge, Strachey developed an interest in engineering. She was discouraged by her mother Mary Berensen but nevertheless she took an electrical engineering class at Oxford University in 1910 and planned to study electrical engineering at the Technical College of the City and Guilds of London Institute in October 1910. She wrote to her aunt “I have decided to go to London next winter for my engineering” and that she had been encouraged and helped by Hertha Ayrton. She abandoned her plan due to marriage, but maintained her involvement with the Society of Women Welders which she had helped to found.