Horst Pinnow (b. 1936) is a German actor who appeared on Sesamstrasse in the recurring "Letter Detectives" series of filmed inserts. He played detective Humphrey Gocart Jr., with Tobias Meister as his assistant Ludwig Lupe.
Pinnow began his acting career on stage and has been active in German film and television since the 1970s. He was familiar in made-for-television plays and movies and in episodes of Tatort, Der Hausgeist, and the monkey sitcom Unser Charly. He was a regular on the family drama Die Wicherts von nebenan as Alwin Barthold and later appeared in the 2009 film Dinosaurier, a caper comedy about senior citizens. His voice has been heard on German radio, in audio dramas on records and cassettes, and in dubbing (including the cartoon Alfred J. Kwak).