| Residence: | Madison, Wisconsin, U.S. |
| Birth Date: | 1996 9, df=yes |
| Birth Place: | Dublin, Ireland |
| Height: | 1.93m (06.33feet) |
| Plays: | Right-handed (two-handed backhand) |
| Careerprizemoney: | $$37,402 |
| College: | Wisconsin Badgers |
| Singlesrecord: | 1–3 (at ATP Tour level, Grand Slam level, and in Davis Cup) |
| Singlestitles: | 0 |
| Highestsinglesranking: | No. 732 (22 May 2023) |
| Currentsinglesranking: | No. 1073 (27 March 2024) |
| Doublesrecord: | 0–2 (at ATP Tour level, Grand Slam level, and in Davis Cup) |
| Doublestitles: | 0 |
| Highestdoublesranking: | No. 587 (2 February 2024) |
| Currentdoublesranking: | No. 604 (27 March 2024) |
| Updated: | 27 March 2024 |
Osgar O'Hoisin (Osgar Ó hOisín; born 3 September 1996) is an Irish tennis player. He has a career high ATP singles ranking of No. 732 achieved on 22 May 2023, and a career high doubles ranking of No. 587 achieved on 2 February 2024.
He attended the University of Wisconsin–Madison, and played for the Wisconsin Badgers tennis team between 2015 and 2019.
O'Hoisin is a multiple time club champion in his boyhood club Donnybrook Tennis Club, in Dublin, Ireland.[1] He was Irish under-18 champion in 2012 and 2015.[2]
O'Hoisin has represented Ireland at the Davis Cup since 2018. He has a win–loss record of 2–4 in singles and 3–1 in doubles. In 2022 he won the deciding match in Ireland's 3–2 win against Barbados in the World Group II competition.[3]