Kitshoff first broke through during the 2011 season, making 5 substitute appearances for the Stormers and then 5 Currie Cup appearances for Western Province while still only a teenager. He became more of a regular during 2012, nailing down the number 1 jersey for both the Stormers and Western Province and also winning the Currie Cup title with Province in an impressive win over the Sharks in Durban. His 2013 Super Rugby campaign was solid and he carried that form into the Currie Cup later in the year where he was an ever-present as Province reached a second consecutive Currie Cup final this time going down at home to the Sharks. 2014 was a year of frustration as he succumbed to a season-ending injury towards the back-end of the Super Rugby season and this ruled him out of Western Province's successful Currie Cup campaign in which they lifted the title for the second time in three years with a narrow win over the Golden Lions at Newlands.[citation needed]
In February 2015, it was revealed that Kitshoff would join FrenchTop 14 side Bordeaux at the conclusion of the 2015 Currie Cup Premier Division season.[4] He spent two seasons in France before returning to Cape Town in 2017.[5] In his second stint with the Stormers, he was named captain of the team in 2021,[6] and led the team as they won the inaugural United Rugby Championship in 2022.[7] He signed for Ulster ahead of the 2023–24 season,[8] and returned to the Stormers at the end of the season.[9]
Following his return from Ulster, Steven Kitshoff suffered a serious neck injury during the Currie Cup match against Griquas.
Following medical advice, he underwent neck fusion surgery on 20 November to aid in his recovery.[10]