Horst Sellentin (14 September 1922 – 10 May 1973) was a German baritone and a choral conductor.
Born in Berlin, Sellentin studied instrumental music, voice and conducting.
He worked at the Theater Lübeck from 1946 to 1948.
From 1948 he was a singer of the NDR Chor in Hamburg who also appeared as a soloist.
In 1960, he co-founded with Max Thurn the boys' choir of the NDR, called Knabenchor des Norddeutschen Rundfunks in Hamburg and was its director.
When the choir became part of the new church St.
Nikolai (Hamburg), the name was changed to Hamburger Knabenchor St.