Lorens Marmstedt
- Birthday: 1908-10-29
- Deathday: 1966-04-04
- Place of birth: Stockholm, Stockholms län, Sweden
Enterprising and audacious film and theater producer who fostered a new generation of Swedish film directors in the 1940s via his own company, Terrafilm, Marmstedt had a profound influence on the young Ingmar Bergman, whom he also engaged as a theater director at his own Intima Theatre in Stockholm.
