Willem Stephanus Britz (born 31 August 1988) is a South African rugby union player, currently playing with the Free State Cheetahs.
At youth level, he represented Griquas at the U18 Craven Week tournaments in 2005 and 2006. He also played for them in the U19 Currie Cup tournament in 2006 before moving to the Free State Cheetahs. He made his debut for the Cheetahs in the 2009 Vodacom Cup game against the Mighty Elephants.
He then moved to the Griffons in 2010, where he became a regular in the team over the next 3 seasons. He played another 4 games for the Cheetahs during the 2011 Vodacom Cup season and also represented UFS Shimlas in the Varsity Cup during the 2008, 2009, 2010, 2011 and 2012 seasons.
He joined the Golden Lions just before the start of the 2012 Currie Cup Premier Division season and made his Golden Lions debut in their first game of the season against his former team, the Cheetahs.
He played in both legs of the Lions' promotion/relegation matches after the 2013 Super Rugby season, which saw the Lions regain their spot in Super Rugby.