- Gender: Male
- Birthday: 1897-04-26
- Day of Death: 1987-01-14 ( 90 years old )
- Place of Birth: Hamburg, Germany
- Also Known As: Hans Detlef Sierck / Detlef Sierck / Michael O'Hara
Douglas Sirk (born Hans Detlef Sierck; April 26, 1897 – January 14, 1987) was a Danish-German film director best known for his work in Hollywood melodramas in the 1950s.