Ruth Williams Khama, Lady Khama (9 December 1923 – 22 May 2002) was the wife of Botswana's first president Sir Seretse Khama, the Paramount Chief of its Bamangwato tribe. Lady Khama was a former WAAF ambulance driver from Blackheath, London. She met the then Prince Seretse Khama while he was attending law school in England and she was working as a clerk at Lloyd's of London. Their interracial marriage in 1948 provoked discomfort in both South Africa and, initially, Botswana, and they lived as exiles in England until 1956. They then moved to Botswana. Lady Khama was an influential, politically active first lady during her husband's tenure as president, 1966–1980.
Her sons Ian and Tshekedi became prominent politicians in Botswana.
She died of throat cancer at the age of 79.
A film, A Marriage of Inconvenience, based on the Michael Dutfield book with same name, was made in 1990 about the Khamas. A book, Colour Bar, has been published about the Khamas' relationship and struggles.