Horst Stark (b. 1934) is a German voice actor who dubbed Lefty (known as Schlemihl) on Sesamstrasse beginning around 1976, and also voiced Sherlock Hemlock at one point. He has also used the "Schlemihl" voice in German radio commercials.
For German TV, Stark was the voice of Pernell Roberts on Bonanza, William Shatner in an episode of Mannix, Richard Roundtree in Roots, Tom Selleck on The Rockford Files, Maurice Evens as the Puzzler on Batman, James Fox on Poirot, and Martin Landau and other guest stars on Columbo. Film dubs include Peter Sellers in The Millionairess and Vincent Price in The Mad Magician.
Stark's son is dubbing actor Christian Stark.