| Guy Mercer | |
| Birth Date: | 12 December 1989 |
| Birth Place: | Bristol, England |
| Weight: | 100kg (200lb) |
| Ru Currentteam: | Ospreys |
| Ru Position: | Flanker |
| Ru Clubyears: | 2010– 2017–18 |
| Ru Proclubs: | Bath → Ospreys (loan) |
| Ru Clubcaps: | 123 16 |
| Ru Clubpoints: | (25) (0) |
| Ru Clubupdate: | 30 August 2017 |
| Ru Nationalyears: | |
| Ru Nationalteam: | England U16 |
| School: | King Edward's School |
Guy Mercer (born 12 December 1989) is a former English rugby union player for Bath in the Aviva Premiership, who last played on loan to Welsh Pro14 side Ospreys. His position of choice was flanker.
Mercer was promoted from the academy in the 2009–2010 season. He was named man-of-the-match in Bath's Aviva Premiership loss to Wasps in 2010 and was named club captain in 2016.
In August 2017, Mercer joined Welsh Pro14 side Ospreys on a season-long loan deal, joining in time for the opening round of the 2017–18 Pro14 season.[1]