| 2021-05-22 11:44:57Saturday, May 22, 2021 | Eastbourne Eagles v Newcastle Diamonds | 11:44:57Postponed | P - P | Championship | Arlington Stadium |
| 2021-06-04 19:30:59Friday, June 4, 2021 | Edinburgh Monarchs v Newcastle Diamonds | 19:30:597:30 pm | 47 - 43 | Championship KO Cup, 1st Round, 1st Leg | Armadale Stadium |
| 2021-06-06 16:00:55Sunday, June 6, 2021 | Newcastle Diamonds v Edinburgh Monarchs | 16:00:554:00 pm | 38 - 52 | Championship KO Cup, 1st Round, 2nd Leg | Newcastle Stadium |
| 2021-06-11 19:30:26Friday, June 11, 2021 | Scunthorpe Scorpions v Newcastle Diamonds | 19:30:267:30 pm | 57 - 33 | Championship | Eddie Wright Raceway |
| 2021-06-20 16:00:55Sunday, June 20, 2021 | Newcastle Diamonds v Leicester Lions | 16:00:554:00 pm | 49 - 41 | Championship | Newcastle Stadium |
| 2021-06-26 19:00:16Saturday, June 26, 2021 | Leicester Lions v Newcastle Diamonds | 19:00:167:00 pm | 63 - 27 | Championship | Paul Chapman & Sons Arena |
| 2021-06-27 00:05:55Sunday, June 27, 2021 | Newcastle Diamonds v Plymouth Gladiators | 00:05:55Postponed | P - P | Championship | Newcastle Stadium |
| 2021-06-29 00:05:30Tuesday, June 29, 2021 | Plymouth Gladiators v Newcastle Diamonds | 00:05:30Postponed | P - P | Championship | Plymouth Coliseum |
| 2021-07-03 19:00:55Saturday, July 3, 2021 | Berwick Bandits v Newcastle Diamonds | 19:00:557:00 pm | 51 - 39 | Championship | Shielfield Park |
| 2021-07-04 16:00:55Sunday, July 4, 2021 | Newcastle Diamonds v Scunthorpe Scorpions | 16:00:554:00 pm | 52 - 38 | Championship | Newcastle Stadium |
| 2021-07-09 19:30:24Friday, July 9, 2021 | Glasgow Tigers v Newcastle Diamonds | 19:30:247:30 pm | 55 - 35 | Championship | Peugeot Ashfield Stadium |
| 2021-07-16 19:30:43Friday, July 16, 2021 | Edinburgh Monarchs v Newcastle Diamonds | 19:30:437:30 pm | 58 - 32 | Championship | Armadale Stadium |
| 2021-07-23 19:30:02Friday, July 23, 2021 | Redcar Bears v Newcastle Diamonds | 19:30:027:30 pm | 39 - 21 | Championship | Media Prima Arena |
| 2021-07-25 16:00:55Sunday, July 25, 2021 | Newcastle Diamonds v Redcar Bears | 16:00:554:00 pm | 35 - 55 | Championship | Newcastle Stadium |
| 2021-08-01 16:00:55Sunday, August 1, 2021 | Newcastle Diamonds v Berwick Bandits | 16:00:554:00 pm | 49 - 40 | Championship | Newcastle Stadium |
| 2021-08-08 16:00:55Sunday, August 8, 2021 | Newcastle Diamonds v Poole Pirates | 16:00:554:00 pm | 29 - 61 | Championship | Newcastle Stadium |
| 2021-08-08 18:00:58Sunday, August 8, 2021 | Newcastle Diamonds v Plymouth Gladiators | 18:00:586:00 pm | 45 - 33 | Championship | Newcastle Stadium |
| 2021-08-15 18:30:55Sunday, August 15, 2021 | Newcastle Diamonds v Glasgow Tigers | 18:30:556:30 pm | 48 - 42 | Championship | Newcastle Stadium |
| 2021-08-22 16:00:55Sunday, August 22, 2021 | Newcastle Diamonds v Kent Kings | 16:00:554:00 pm | 45 - 45 | Championship | Newcastle Stadium |
| 2021-08-24 18:30:59Tuesday, August 24, 2021 | Kent Kings v Newcastle Diamonds | 18:30:596:30 pm | 56 - 34 | Championship | Central Park Stadium |
| 2021-08-25 19:30:22Wednesday, August 25, 2021 | Poole Pirates v Newcastle Diamonds | 19:30:227:30 pm | 59 - 31 | Championship | Poole Stadium |
| 2021-08-31 19:00:47Tuesday, August 31, 2021 | Plymouth Gladiators v Newcastle Diamonds | 19:00:477:00 pm | 48 - 42 | Championship | Plymouth Coliseum |
| 2021-09-12 18:30:55Sunday, September 12, 2021 | Newcastle Diamonds v Edinburgh Monarchs | 18:30:556:30 pm | 42 - 48 | Championship | Newcastle Stadium |
| 2021-09-19 18:30:55Sunday, September 19, 2021 | Newcastle Diamonds v Birmingham Brummies | 18:30:556:30 pm | 44 - 45 | Championship | Newcastle Stadium |
| 2021-09-22 19:30:09Wednesday, September 22, 2021 | Birmingham Brummies v Newcastle Diamonds | 19:30:097:30 pm | 55 - 35 | Championship | Perry Barr Stadium |
