Marianna Kaat
- Birthday: 1957-12-07
- Place of birth: Tallinn, Estonian SSR, USSR [now Estonia]
- Also know as: Марианна Каат
Marianna Kaat (December 7, 1957) is an Estonian film and television director and producer. She is a graduate from the St.Petersburg State Theatre Arts Academy in Russia. In 1998, she founded the Tallinn-based independent production company Baltic Film Production (BFP).
