Jason Jenkins

2014

After completing high school at St. Alban's College in Pretoria, Jenkins joined the Blue Bulls Academy. He established himself in the Blue Bulls U19 squad that participated in the 2014 Under-21 Provincial Championship, appearing in all fourteen of their matches in the competition and starting thirteen of those. He scored tries in their matches against the Sharks U19s and the Western Province U19s to help the Blue Bulls finish top of the log to qualify for the semi-finals. He helped the Blue Bulls to a 43–20 victory in their semi-final match against the Sharks U19s and he also started the final, where the Blue Bulls lost 26–33 to Western Province.

2015

In 2015, Jenkins was named in the UP Tuks squad for the 2015 Varsity Cup competition. He make one appearance, playing off the bench in a 63–8 victory over the CUT Ixias.

Jenkins was named in a 37-man South Africa Under-20 training squad and appeared for them as a replacement in a 31–24 victory in a friendly match against a Varsity Cup Dream Team that was named at the conclusion of the 2015 Varsity Cup competition. He was then named in their squad to tour Argentina for a two-match series as preparation for the 2015 World Rugby Under 20 Championship. He started their 25–22 victory over Argentina in the first match, as well as 39–28 win in the second match four days later.

Upon the team's return, he was named in the final squad for the 2015 World Rugby Under 20 Championship. He played in all three of their matches in Pool B of the competition; he played off the bench in a 33–5 win against hosts Italy, before starting both their 40–8 win against Samoa and their 46–13 win over Australia. Jenkins also scored a try in each of the two matches that he started to help South Africa finish top of Pool B to qualify for the semi-finals with the best record pool stage of all the teams in the competition. He started their semi-final match against England, but could not prevent them losing 20–28 to be eliminated from the competition by England for the second year in succession. He started their third-place play-off match against France, scoring his third try of the competition to help South Africa to a 31–18 win to win the bronze medal.

He then played for the Blue Bulls U21s in the 2015 Under-21 Provincial Championship Group A, but was also named in the senior squad for the 2015 Currie Cup Premier Division.

South Africa 'A'

In 2016, Jenkins was included in a South Africa 'A' squad that played a two-match series against a touring England Saxons team. He didn't play in their first match in Bloemfontein, but started the second match of the series, a 26–29 defeat in George.

Toyota Verblitz

He joined Japanese Top League side Toyota Verblitz for the 2017–18 season.