The 1990 Cincinnati Open, was a tennis tournament played on outdoor hard courts. It was the 91st edition of the tournament and was part of the 1990 ATP Tour. It took place in Cincinnati, Ohio, United States from August 13 through August 20, 1990. Ken Flach and Robert Seguso were the defending champions, but lost in the second round to Sven Salumaa and Byron Talbot. Darren Cahill and Mark Kratzmann won in the final, 7–6, 6–2, against Neil Broad and Gary Muller.
Jeremy Bates and Kevin Curren were the defending champions but they competed with different partners that year, Bates with Nick Brown and Curren with Neil Broad.
John Fitzgerald and Anders Järryd were the defending champions but lost in the first round to Jonathan Canter and Bruce Derlin.
Todd Woodbridge and Mark Woodforde defeated Grant Connell and Patrick Galbraith in the final, 7–5, 6–3, 7–6(7–4) to win the gentlemen's doubles title at the 1993 Wimbledon Championships. It was the Woodies' first Wimbledon title, their second major title overall, and their second step towards the career Super Slam.
Paul Annacone and Christo van Rensburg were the defending champions. Annacone participated with John Fitzgerald, and lost in the quarterfinals to Scott Davis and David Pate, while Van Rensburg played with Kevin Curren, and lost in the semifinals to Grant Connell and Glenn Michibata.
Rick Leach and Jim Pugh defeated Connell and Michibata 3–6, 6–4, 6–2, in the final.
Rick Leach and Jim Pugh were the defending champions, but lost in the semifinals to Grant Connell and Glenn Michibata.
Pieter Aldrich and Danie Visser won the title, defeating Connell and Michibata 6–4, 4–6, 6–1, 6–4, in the final.
Pieter Aldrich and Danie Visser were the defending champions, but lost in the first round to Paul Haarhuis and Mark Koevermans.
Scott Davis and David Pate won the title, defeating Patrick McEnroe and David Wheaton 6–1, 4–6, 6–4, 5–7, 9–7, in the final. This was Pate's first Grand Slam title and final, despite gaining the World No. 1 ranking two weeks earlier.
John Fitzgerald and Anders Järryd lost in the third round to McEnroe and Wheaton. It was their only Grand Slam loss of the year, as they would go on to win the following three majors in 1991.
The men's doubles tournament at the 1990 French Open was held from 28 May until 10 June 1990 on the outdoor clay courts at the Stade Roland Garros in Paris, France. Sergio Casal and Emilio Sánchez won the title, defeating Goran Ivanišević and Petr Korda in the final.
John Fitzgerald and Anders Järryd defeated Javier Frana and Leonardo Lavalle in the final, 6–3, 6–4, 6–7(7–9), 6–1 to win the gentlemen's doubles title at the 1991 Wimbledon Championships. It was Fitzgerald and Järryd's third Wimbledon final in four years.
The men's doubles event at the 1991 French Open tennis tournament was held from 27 May until 9 June 1991 on the outdoor clay courts at the Stade Roland Garros in Paris, France. John Fitzgerald and Anders Järryd won the title, defeating Goran Ivanišević and Petr Korda in the final.
Andre Agassi and Petr Korda were the defending champions, but Agassi did not compete this year. Korda teamed up with Stefan Edberg and lost in second round to Cyril Suk and Daniel Vacek.
Neil Broad and Gary Muller were the defending champions, but lost in the second round to Kent Kinnear and Brad Pearce.
Andre Agassi was the defending champion and successfully defended his title, by defeating Petr Korda 6–3, 6–4 in the final.
Grant Connell and Glenn Michibata were the defending champions, but lost in the semifinals to tournament runners-up Ken Flach and Robert Seguso.
Patrick Galbraith and Todd Witsken were the defending champions, but competed this year with different partners.
Todd Woodbridge and Mark Woodforde were the defending champions, but Woodbridge did not compete this year. Woodforde teamed up with Jason Stoltenberg and lost in the first round to tournament winners Andre Agassi and Petr Korda.
Patrick Galbraith and Danie Visser were the defending champions, but competed this year with different partners. Galbraith teamed up with Grant Connell and lost in the semifinals to Jim Courier and Mark Knowles, while Visser teamed up with Laurie Warder and lost in the second round, also to Courier and Knowles.
Stefan Edberg and Petr Korda were the defending champions, but lost in the first round to Gary Muller and Danie Visser.
Tomáš Šmíd and Petr Korda were the defending champions, but Korda chose not to participate. Šmid partnered Karel Nováček, but lost in the first round to Ronnie Bathman and Rikard Bergh.
Paul Annacone and David Wheaton were the defending champions, but Wheaton chose not to participate. Annacone partnered with Doug Flach, but lost to Jim Grabb and Richey Reneberg in the first round.
Ken Flach 
Grant Connell 
