Rex Maynard Linn is an American film and television actor. He is best known for playing the role of Frank Tripp in the television series CSI: Miami. Linn was born in Spearman, Texas, the third child, and second son, of Darlene (née Deere) and James Paul Linn. In August 1969, his parents relocated the family to Oklahoma City, Oklahoma, where his father practiced law. There he attended Heritage Hall and later Casady School, an independent school affiliated with the Episcopal Church, and was employed part-time at the Oklahoma City Zoo. In November 1975, after seeing Jack Nicholson in One Flew Over the Cuckoo's Nest, Linn announced he was an actor.  In his high-school production of Fiddler on the Roof, after Linn demolished a set during a number, his drama coach ordered him off the set and advised him to direct his energy to some other field of endeavor, ending Linn's high-school acting career. He graduated from Oklahoma State University in 1980 with a degree in Broadcast Journalism with an emphasis in Radio-TV-Film from the School of Journalism and Broadcasting, renamed School of Media and Strategic Communications.

In 1989, he was cast in his first substantial role, as serial killer Floyd Epps, in Night Game, starring Roy Scheider. Following this film, and a part as the sheriff in a 1990 episode of The Young Riders (titled "Hard Time"), he decided it was time to head west. He began with small roles in theatrical films such as My Heroes Have Always Been Cowboys (1991). Since then he has appeared in more than 35 films and numerous television series, including Young Sheldon (2017-2024). He is currently in pre-production on the sit-com, Happy’s Place, starring his real-life girlfriend, country singer and actress, Reba McEntire.