Originally from Greenwich in London, Jackson began playing rugby at Blackheath F.C., progressing through the club's minis and junior sections.[2] He was recruited into the Saracens junior academy as a teenager, and represented their under-18s team in 2019.[3] That same year, he became a designated England Academy Player while attending Sutton Valence School,[4] and also represented the England Under-18s.[5]
Between 2020 and 2021, Jackson joined the academy at Ealing Trailfinders, to coincide with his studies at Brunel University.[6] During this time, he received his first call-up to the England Under-20s.[7] Subsequently, he renewed his contract with Saracens the following year, on a senior academy deal.[8]
Jackson made his senior debut for Saracens against London rivals Harlequins in the 2021–22 Premiership Rugby Cup pool stage, followed by his first Premiership appearance as a substitute against Wasps in January 2022.[9] Over the following two years, he was dual-registered with Ampthill and played the majority of his rugby in the RFU Championship, whilst also featuring for his parent club in the Premiership Cup.[10] Jackson was notably Ampthill's top try scorer during the 2023–24 Championship season, crossing the whitewash 14 times in 17 appearances for the team.[11]
Ahead of the 2024–25 Premiership season, Jackson was promoted into the Saracens senior squad, before earning his first league start against Northampton Saints in December 2024.[12] He also finished the 2024–25 cup campaign as the club's top try scorer, touching down 7 times in 6 matches.[13]