After a third straight loss on Sunday against Moana Pasifika, McDermott was outed by the Super Rugby Pacific foul play review committee (FPRC) after receiving a red card for striking Irie Papuni with a swinging arm while bringing him to ground in a tackle.
McReight was suspended for a high tackle on William Havili later in Queensland's 17-14 defeat in Whangarei.
The two Wallabies' bans could not have come at a worse time for Les Kiss's outfit, reeling from successive losses to the Western Force, the ACT Brumbies, and Moana Pasifika.
In its findings, the FPRC said the "entry point" of suspensions for McDermott's offence was six weeks, assessed as "mid-range for intentional and deliberate physical abuse of striking with arm to the side of the victim player's head where the victim player was in an vulnerable position with limited ability, if any, to defend himself".
McDermott was, however, given a three-week "discount" for an early guilty plea, and other mitigating factors including remorse and a prior exemplary disciplinary record.
Of McReight's hit, the FPRC said: "The FPRC was concerned by the 'upright nature of the tackle' and determined that it was an 'always illegal' act of foul play.
"In those circumstances mitigation would not apply," it said in a statement.
The suspensions for both Reds extend up to and including May 4, meaning they can not play in that day's fixture against the Crusaders, but can return against the Melbourne Rebels on Friday, May 10.
Queensland have now slid to sixth on the Super Rugby Pacific ladder, going from 3-1 to 3-4.
11°C