Born in Paddington, London to Jamaican immigrants she went to Harrow City Girls' School and then Newnham College, Cambridge. After leaving university she became a researcher for Thames Television. Between 1976-1980 she was a civil servant and then between 1982-1987 a journalist. In the late 1980s she became the press officer of the Greater London Council (then led by Ken Livingstone).
Diane Abbott was married to David Thompson until a divorce in the mid-90s, she has one son by that marriage.
She attracted criticism from all political parties in late October 2003, after revealing her decision to send her son to the City of London School, one of the top private schools in the country, after having criticised Attorney General Harriet Harman for sending her son to a selective, although state, school in Orpington, Kent, and Tony Blair for sending his son to a similar school, the Brompton Oratory (which is also officially a state school)