Klaas-Jan de Groot is a Dutch conductor and choir director. He has been Choir Director at the Zurich Opera House since the 2025/26 season.

After studying in The Hague and Cardiff, he served as assistant to Chorus Director Ching-Lien Wu at the Dutch Opera in Amsterdam from 2016 to 2022, where he rehearsed several productions and projects with the opera chorus. Since 2018, he has worked regularly with the Dutch Radio Choir (Groot Omroepkoor). From 2018 to 2024, he served annually as assistant to Chorus Master Eberhard Friedrich at the Bayreuth Festival. He has conducted various concerts and performances with Opera Zuid, as well as with the Orchestra of the 18th Century and the Essen Philharmonic Orchestra. From 2022 to 2025, he was Chorus Master at the Aalto Theatre in Essen. He works regularly with the NDR Vocal Ensemble and the Berlin Radio Choir. In 2024, he made his debut with the MDR Radio Choir. As part of a programme to promote emerging talent, Klaas-Jan de Groot was awarded the prestigious Dutch conducting prize from the Anton Kersjes Fund in 2021.