Jackson was recruited by Melbourne with pick 3 in the 2019 AFL draft.[11][12][13] Jackson debuted in the Demons' one-point win over the Carlton Blues in the second round of the 2020 AFL season.[14] He collected 7 disposals, 1 behind and 1 tackle.[15] After being omitted for the next 3 rounds, Jackson re-entered the team in Round 7. He won the Rising Star nomination for Round 10.[16][17][18] In that game he kicked 2 goals, including the opening goal. On top of that, he also collected 8 disposals, 14 hitouts and 2 marks.[19] At the conclusion of the year he took out the Harold Ball Memorial Trophy, an award given to the best young talent for the Melbourne Demons.[20] Jackson re-signed for a one-year contract extension at the end of the year, keeping him at the club until 2022.[1]
Jackson became a part of a select few players in the AFL to receive two Rising Star nominations in their careers after he received a 2021 AFL Rising Star nomination for his 22 disposal, 1 goal performance in Round 7 of the 2021 AFL season,[21] and won the award overall at the season's conclusion.[22] Jackson was a part of Melbourne's 57 year drought breaking Grand Final victory over the Western Bulldogs.[23]
Following Melbourne's loss to the Brisbane Lions in the 2022 semi-final, Jackson reportedly met with the club and formally requested a trade to his home state of Western Australia, however he did not nominate a specific club and allowed offers from both West Coast and Fremantle.[24] Jackson was traded to Fremantle on 10 October for a first-round pick, a future first-round pick and a future second-round pick.[25] Upon joining Fremantle Jackson signed a seven year contract tying him to Fremantle until at least 2029.[26]
He made his debut for Fremantle in round one of the 2023 AFL season against St Kilda at Optus Stadium. Round 15 saw Jackson collect 17 disposals, 9 score involvements and kick three goals during Fremantle's 32 point win over Essendon.[27]Western Derby 57 saw Jackson collect 19 disposals, 26 hitouts and kick a goal in Fremantle's win over West Coast. He finished the game equal best on ground after tying with Lachie Schultz for the Glendinning–Allan Medal.[28] He finished his first season at Fremantle with a fourth place finish in the club's fairest and best award.[29]
He was ranked the sixth best ruckman in the league by Nine's Wide World of Sports in February 2024.[30] Jackson made the line-up for Fremantle's opening game of the 2024 AFL season against the Brisbane Lions at Optus. He was named as the sole ruckman after fellow ruckman and teammate Sean Darcy was ruled out due to injury.[31] Jackson was impressive collecting 30 hit-outs and kicking two goals in the 23 point come from behind win.[32] He was arguably Fremantle's best player the next week against North Melbourne at Marvel Stadium, collecting 24 disposals, 21 hit-outs, two goals and 10 score involvements.[33]
^The 2020 season was played with 17 home-and-away matches per team (down from 22) and 16-minute quarters with time on (down from 20-minute quarters with time on) due to the impact of the COVID-19 pandemic.
^2022 statistics include one game in which Jackson was substituted out of the game due to injury (round 23) and was replaced by James Jordon.