*Club domestic league appearances and goals, correct as of 22:44, 30 December 2024 (UTC). ‡ National team caps and goals, correct as of 21:26, 30 June 2017 (UTC)
Kempf started his career at Eintracht Frankfurt, appearing for both the reserves and the senior team.
On 15 July 2014, Kempf joined SC Freiburg on an immediate transfer from Frankfurt. The transfer fee reportedly amounted to €800,000.[3]
On 14 May 2018, Kempf signed a four-year-contract with VfB Stuttgart, enabling him to join the team on a free transfer on 1 July 2018.[4]
On 25 January 2022, Kempf signed a contract with Hertha BSC until 2026.[5]
On 28 August 2024, Kempf moved to Como in Italy on a three-season contract.[6]