Castle Rock Entertainment | 2,100 followers on LinkedIn. Castle Rock Entertainment was co-founded by Oscar-nominated filmmaker Rob Reiner. The company has produced over 125 movies including When Harry Met Sally, A Few Good Men, City Slickers, The Shawshank Redemption, as well as one of the successful comedy series of all-time, Seinfeld. In 2021 it relaunched the film division with a $175M fund.