|Country (sports)||/ South Africa|
|Born||27 December 1964|
Durban, South Africa
|Height||1.90 m (6 ft 3 in)|
|Plays||Left-handed (one-handed backhand)|
|Highest ranking||No. 49 (6 August 1990)|
|Grand Slam Singles results|
|Australian Open||3R (1987)|
|French Open||2R (1991)|
|US Open||3R (1990)|
|Highest ranking||No. 7 (15 November 1993)|
|Grand Slam Doubles results|
|Australian Open||SF (1990)|
|French Open||QF (1991)|
|Wimbledon||SF (1988, 1993)|
|US Open||SF (1986)|
Gary Muller (born 27 December 1964) is a former professional South African tennis player.
Muller turned pro in 1985. His 12-year career included wins over Andre Agassi, Jim Courier, Michael Chang and Stefan Edberg. Muller's best singles result at a Grand Slam was reaching the third round in the 1987 Australian Open in which he lost to Miloslav Mečíř of Czechoslovakia. A more successful doubles player than singles, Muller won eight doubles titles in his career with six different partners and reached a career highest ranking of 7th in November 1993. He reached the semi-final of the men's doubles at four Grand Slams (1986 US Open, 1988 Wimbledon, 1990 Australian Open and 1993 Wimbledon). Muller still holds the record for the most aces served in a three set match (54) in a 1993 Wimbledon Qualifying match against Peter Lundgren.
After his retirement in 1997 Muller worked for eight years as an ATP Tour coach during which time he worked with Jonas Björkman, Stefan Koubek, Sargis Sargsian and Thomas Johansson. He was with Dominic Thiem as his Touring Coach when he clinched the title in Rio in 2017.
He currently resides in Ontario, Canada with his wife and four children.
Doubles (8 wins, 12 losses)
|Win||1.||Jul 1987||Schenectady, U.S.||Hard||Gary Donnelly|| Brad Pearce
|Loss||1.||Nov 1988||Johannesburg, South Africa||Hard (i)||Tim Wilkison|| Kevin Curren
|Win||2.||Jul 1989||Washington, U.S.||Hard||Neil Broad|| Jim Grabb
|6–7, 7–6, 6–4|
|Loss||2.||Aug 1990||Cincinnati, U.S.||Hard||Neil Broad|| Darren Cahill
|Loss||3.||Sep 1990||Basel, Switzerland||Hard (i)||Neil Broad|| Stefan Kruger
Christo van Rensburg
|6–4, 6–7, 3–6|
|Win||3.||Oct 1990||Toulouse, France||Hard||Neil Broad|| Michael Mortensen
|Win||4.||Jul 1991||Gstaad, Switzerland||Clay||Danie Visser|| Guy Forget
|Win||5.||Oct 1991||Vienna, Austria||Carpet (i)||Anders Järryd|| Jakob Hlasek
|Loss||4.||Feb 1992||Memphis, U.S.||Hard (i)||Kevin Curren|| Todd Woodbridge
|5–7, 6–4, 6–7|
|Win||6.||Apr 1992||Seoul, South Korea||Hard||Kevin Curren|| Kelly Evernden
|Loss||5.||Apr 1993||Seoul, South Korea||Hard||Neil Broad|| Jan Apell
|7–5, 6–7, 2–6|
|Loss||6.||Jun 1993||London/Queen's Club, U.K.||Grass||Neil Broad|| Todd Woodbridge
|7–6, 3–6, 4–6|
|Loss||7.||Jul 1993||Stuttgart, Germany||Clay||Piet Norval|| Tom Nijssen
|Win||7.||Oct 1993||Lyon, France||Carpet (i)||Danie Visser|| John-Laffnie de Jager
|Loss||8.||Oct 1993||Stockholm, Sweden||Carpet (i)||Danie Visser|| Todd Woodbridge
|1–6, 6–3, 2–6|
|Loss||9.||Jun 1994||Halle, Germany||Grass||Henri Leconte|| Olivier Delaître
|4–6, 7–6, 4–6|
|Loss||10.||Oct 1994||Ostrava, Czech Republic||Carpet||Piet Norval|| Martin Damm
|4–6, 6–1, 3–6|
|Loss||11.||Mar 1995||Indian Wells, USA||Hard||Piet Norval|| Tommy Ho
|Loss||12.||Oct 1996||Beijing, China||Hard (i)||Patrik Kühnen|| Martin Damm
|Win||8.||Feb 1997||San Jose, U.S.||Hard (i)||Brian MacPhie|| Mark Knowles
|4–6, 7–6, 7–5|
- "Les records d'aces sur un match - Tennis Legend". Tennis Legend (in French). Retrieved 7 June 2016.
- Ottawa, Harald (27 February 2017). "Für Dominic Thiem geht es von Rio nach Acapulco und Miami" (in German).
- "Gary Muller | Bio | ATP World Tour | Tennis". ATP World Tour. 17 April 2017.