Jason Deneen Beghè (born March 12, 1960) is an American film and television actor and critic of Scientology. He is best known for his starring role as sergeant Hank Voight on the NBC TV series Chicago P.D. and for starring in the 1988 George A. Romero film Monkey Shines. He's also known for playing Demi Moore's love interest in G.I. Jane, appearing as a police officer in the film Thelma & Louise, starring opposite Moira Kelly on the series To Have & to Hold, and having recurring roles on Picket Fences, Melrose Place, Chicago Hope, American Dreams, Cane, and Californication.

He began taking Scientology courses in 1994, and later appeared in a Church of Scientology advertising campaign and in promotional videos. According to Beghe, Church of Scientology head David Miscavige referred to him as "the poster boy for Scientology". Beghe left Scientology in 2007 and began publicly speaking out about his experiences within the church in April 2008. An on camera interview with Beghe about his experiences in Scientology conducted by Xenu TV founder and journalist Mark Bunker was published to the video site YouTube and later Vimeo. Marina Hyde of The Guardian newspaper called Beghe a Scientology celebrity whistleblower for his actions.

As a young man he attended the Collegiate School in New York City, where he became best friends with John F. Kennedy, Jr. and David Duchovny.