Head to Head
| Premiership Rugby Shield | 2017/09/11 18:30 | London Irish A v Harlequins | W | 7-45 |
| Premiership Rugby Shield | 2015/12/28 15:00 | Harlequins v London Irish A | W | 34-7 |
| Premiership Rugby Shield | 2014/12/15 19:30 | London Irish A v Harlequins | W | 7-12 |
Home History
| Premiership Rugby | 2019/12/21 15:00 | Wasps v Harlequins | W | 22-28 |
| European Rugby Champions Cup | 2019/12/13 19:45 | Harlequins v Ulster | L | 10-34 |
| European Rugby Champions Cup | 2019/12/07 15:15 | Ulster v Harlequins | L | 25-24 |
| Premiership Rugby | 2019/12/01 15:00 | Harlequins v Gloucester | W | 23-19 |
| Premiership Rugby Shield | 2019/11/25 19:30 | Exeter Braves v Harlequins | L | 45-0 |
| European Rugby Champions Cup | 2019/11/23 17:30 | Harlequins v Bath | W | 15-9 |
| European Rugby Champions Cup | 2019/11/16 17:30 | Clermont v Harlequins | L | 53-21 |
| Premiership Rugby | 2019/11/09 15:00 | Harlequins v Worcester Warriors | L | 14-19 |
Away History
| Premiership Rugby Shield | 2019/12/16 19:00 | London Irish A v Saracens Storm | L | 15-33 |
| Premiership Rugby Shield | 2019/11/25 19:00 | London Irish A v Bristol United | W | 31-15 |
| Aviva A League | 2018/04/16 18:15 | Bristol United v London Irish A | W | 19-33 |
| Aviva A League | 2018/04/09 18:30 | London Irish A v Bristol United | W | 62-5 |
| Premiership Rugby Shield | 2017/11/27 19:30 | Bath United v London Irish A | W | 7-64 |
| Premiership Rugby Shield | 2017/10/02 18:30 | Exeter Braves v London Irish A | L | 47-12 |
| Premiership Rugby Shield | 2017/09/22 18:15 | Bristol United v London Irish A | L | 27-17 |
| Premiership Rugby Shield | 2017/09/11 18:30 | London Irish A v Harlequins | L | 7-45 |