|Full name||Tanya Jane Harford Gemmell|
|Country (sports)||South Africa|
|Born||28 November 1958|
Cape Town, South Africa 
|Height||1.62 m (5 ft 4 in) |
|Grand Slam Singles results|
|Australian Open||1R (1980)|
|French Open||2R (1982)|
|Wimbledon||3R (1980, 1982)|
|US Open||3R (1977)|
|Grand Slam Doubles results|
|Australian Open||2R (1980)|
|French Open||W (1981)|
|US Open||QF (1978, 1981)|
|Grand Slam Mixed Doubles results|
|US Open||1R (1980, 1980)|
In 1981 she won the doubles title at the French Open together with compatriot Rosalyn Fairbank. In the final they defeated Candy Reynolds and Paula Smith in straight sets. Her best result at the Wimbledon Championships was reaching the third round in the singles in 1980 and 1982 as well as the semifinal in the doubles and the quarterfinal in the mixed doubles event.
In 1976 she was a runner-up at the Irish Open. Harford reached the final of the South African Open in 1979 but lost in straight sets to Brigitte Cuypers. With Fairbank she won the doubles title at the WTA Swiss Open in 1981.
She served as chair for the Joburg Gay Pride Festival Company, which was organizing the Johannesburg gay pride parade until the dissolution of the company in April 2013, following controversy over the 2012 edition.
Grand Slam finals
Doubles: 1 (1 title)
|Winner||1981||French Open||Clay||Rosalyn Fairbank|| Candy Reynolds
Singles (1 runner-up)
|Runner-up||1.||3 December 1979||South African Open, Johannesburg||Hard||Brigitte Cuypers||6–7, 2–6|