| Rebecca Best | |
| Birth Date: | 18 January 1964 |
| Birth Place: | Sheffield, England |
| Retired: | Yes |
| Plays: | Right Handed |
| Event: | Women's singles |
| Highest Ranking: | No. 6 |
| Date Of Highest Ranking: | July 1988 |
| Updated: | May 2018 |
Rebecca Best (born 18 January 1964), also known as Rebecca O'Callaghan, is an English-born former professional squash player.[1] She was born in Sheffield, but represented Ireland.[2] She reached a career-high world ranking of 6 in July 1988.[3]