List of Boston Red Sox pitchers with the most losses
| Rank | Player Name | Ls |
| 1 | Tim Wakefield | 122 |
| 2 | Cy Young | 112 |
| 3 | Roger Clemens | 111 |
| 4 | George Winter | 97 |
| 4 | Bob Stanley | 97 |
| 6 | Red Ruffing | 96 |
| 7 | Jack Russell | 94 |
| 8 | Bill Monbouquette | 91 |
| 9 | Bill Dinneen | 85 |
| 10 | Tom Brewer | 82 |
| 11 | Luis Tiant | 81 |
| 12 | Frank Sullivan | 80 |
| 13 | Danny MacFayden | 78 |
| 14 | Mel Parnell | 75 |
| 15 | Bruce Hurst | 73 |
| 16 | Willard Nixon | 72 |
| 16 | Ike Delock | 72 |
| 16 | Joe Dobson | 72 |
| 19 | Dennis Eckersley | 71 |
| 20 | Bill Lee | 68 |
| 21 | Jack Wilson | 67 |
| 22 | Fritz Ostermueller | 65 |
| 22 | Jim Lonborg | 65 |
| 24 | Howard Ehmke | 64 |
| 25 | Dutch Leonard | 63 |
