Bundaberg-born McDermott attended Sunshine Coast Grammar School and made his Australian Mens Sevens debut in 2017 at the Wellington Sevens in January.
Playing for Queensland University in Queensland's Premier Grade rugby competition McDermott spent his debut NRC season with Queensland Country in 2017.
The halfback signed for the Reds for the 2018 Super Rugby season and also went on to skipper the Junior Wallabies for two games during the 2018 U20s World Championships in France.
After 9 appearances for the Reds, McDermott signed a new deal with the squad until at least 2023 following the next Rugby World Cup in France.
He played 14 matches and only missed the final two games of the 2019 season after suffering an ankle injury in Round 16 against the Jaguares.
McDermott had a stellar 2020 campaign with the Queensland Reds in Super Rugby AU starting all nine matches played and scoring 10 points.
In Late 2020, McDermott was called up to the Wallabies as scrum-half under Dave Rennie, which was an extended 44-man squad. He made his debut against the New Zealand national rugby union team in a record 43–5 loss.
In 2021, he made 12 appearances for the Wallabies scoring 2 tries and making 34 runs.
Ahead of the Rugby World Cup 2023, McDermott has been named in the training squad for Australia.
S.C April 2023
|2017 - present|
|2018 - present|
|2020 - present|
|2017 - 2018|
|2018 - 2019|
|2021 - 2021|