Jackson was born in Calvinia, but grew up in Riversdal in the Western Cape, representing the SWD Eagles at various youth levels.
He earned a provincial selection as early as primary school level, when he played as a fly-half at the Under-13 Craven Week held in Kimberley in 2009.
[9] He joined the UP Tuks rugby team – the Pretoria-based university side affiliated to the Blue Bulls Academy – for their 2015 Varsity Cup campaign.
[23] Jackson returned to domestic action in South Africa, appearing in all fourteen of the Blue Bulls U19' matches in the Group A of the 2015 Under-19 Provincial Championship.
[24] While Tinus de Beer was the main goal-kicker for the team, Jackson also contributed 50 points with the boot during the competition, in addition to scoring tries against Golden Lions U19,[25] Free State U19 (first in an away match[26] and then in the return leg at home),[27] Western Province U19[28] and the Sharks U19[29] during the regular season, as well as in their semi-final match against Western Province in a 30–29 victory.
[35] On 10 May 2016, he was included in the final South Africa Under-20 squad for the 2016 World Rugby Under 20 Championship tournament to be held in Manchester, England.