Paul Reiser (; born March 30, 1956) is an American actor, comedian, and television writer. He is known for his roles as Michael Taylor in the 1980s sitcom My Two Dads, Paul Buchman in the NBC sitcom Mad About You, Modell in the 1982 film Diner, Carter Burke in the 1986 film Aliens, and as Detective Jeffrey Friedman in Beverly Hills Cop (1984), Beverly Hills Cop II (1987), and Beverly Hills Cop: Axel Foley. More recently, he has gained recognition for his roles as Jim Neiman in the 2014 film Whiplash and Dr. Sam Owens in the Netflix series Stranger Things.

Reiser is ranked 77th on Comedy Central's 2004 list of the "100 Greatest Stand-ups of All Time". The name of his production company, Nuance Productions, is inspired by one of his lines in the film Diner, where his character explains his discomfort with the word "nuance".

Reiser is arguably best known for his role as greedy, slimy company man Carter Burke in James Cameron's Aliens, in which he went against his casting type and showcased his acting range. He appeared in the second and third seasons of The Kominsky Method as Martin, Mindy Kominsky's boyfriend.