On 1 July 2018, Goretzka officially joined Bayern by signing a four-year contract until June 2022. On 12 August 2018, in the DFL Super Cup, he came on for Thomas Müller in the 64th minute. This was Goretzka's first appearance for Bayern. On 1 September, he scored his first goal for the club in a 3–0 away victory over VfB Stuttgart. The following year, on 19 January 2019, he scored his first ever brace in the Bundesliga, scoring twice in a 3–1 win over Hoffenheim. On 15 February 2019, Goretzka scored an own goal in a Bundesliga game after 13 seconds; no Bayern player had yet touched the ball.