Rain Rannu (born April 2, 1980) is an Estonian screenwriter, movie director, investor and entrepreneur.

He is known as a serial entrepreneur, who is behind Fortumo, a mobile payments technology company sold to Boku in 2020, and a partner at investment fund Superangel. In 2016 he entered movie industry by releasing his first movie Chasing Ponies. In 2021 he released first private movie investment fund in Estonia.