The 1985 Japan Open Tennis Championships (also known as the 1985 Japan and Asian Open Tennis Championships) was a Grand Prix tennis tournament held in Tokyo, Japan. The tournament was held from 14 to 20 October 1985 and was played on outdoor hard courts. Scott Davis and Gabriela Sabatini won the singles titles.
See main article: 1985 Japan Open Tennis Championships – Men's singles. 
Scott Davis defeated Jimmy Arias 6–1, 7–6(7–3)
See main article: 1985 Japan Open Tennis Championships – Women's singles. 
Gabriela Sabatini defeated Linda Gates 6–3, 6–4
See main article: 1985 Japan Open Tennis Championships – Men's doubles. Scott Davis / David Pate defeated Sammy Giammalva Jr. / Greg Holmes 7–6(7–3), 6–7(6–8), 6–3
See main article: 1985 Japan Open Tennis Championships – Women's doubles. 
Belinda Cordwell / Julie Richardson defeated 
Laura Gildemeister / Beth Herr 6–4, 6–4