Sterling joined Chelsea in 2007 at under-8 level and made his under-19 debut in a UEFA Youth League fixture against Sporting CP in December 2014. Although, recently Sterling has been deployed as a wing-back, he has also been played as a winger or centre-forward and impressed during Chelsea's 2015–16 FA Youth Cup campaign, netting in both the semi-final and final. Following an impressive campaign, Sterling was promoted to the U23 squad for the 2016–17 season as a 16 year-old and became a key figure, featuring twenty-four times and scoring four goals. In October 2016, Sterling signed his first professional contract upon his 17th birthday.
On 20 September 2017, Sterling made his Chelsea debut during their EFL Cup tie against Nottingham Forest, replacing Davide Zappacosta during the 5–1 victory.