Otto Schlefenberg (Hebrew: אוטו שלפנברג) (1917–1991) was an Austrian-Israeli footballer and manager.
He is best known for his years at Maccabi Haifa where he started his managerial career.
Born in Austria, Schlefenberg played in Hakoah Vienna before moving to Mandatory Palestine, where he joined Maccabi Haifa, for whom he made his debut in 4 May 1940, in a Liga Bet match against Maccabi Binyamina.
Schalfenberg re-arranged Maccabi Haifa's youth team, Maccabi Shlomo Haifa, and coached it for two years before being appointed as head coach for the club in 1952, a post he held for the next two years, promoting many of the youth team's players, such as Jonny Hardy and Avraham Menchel to the senior side.
[4] In 1962 Schlefenberg returned to Maccabi Haifa, as a replacement for coach Alex Forbes and led the club to winning its first major trophy, the State Cup.