Peter Gerety (born May 17, 1940) is an American actor. On television, he played officer, later detective, Stuart Gharty on Homicide: Life on the Street (1996–1999), Judge Daniel Phelan in The Wire (2002–2008), and Otto Bernhardt in Sneaky Pete (2015–2019).

In film, Gerety has appeared in notable films such as K-Pax, People I Know, The Curse of the Jade Scorpion, Hollywood Ending, Wolf, Charlie Wilson's War, Surviving Picasso, War of the Worlds, Things That Hang from Trees, Inside Man, and Changeling. He is also an accomplished stage actor, appearing in numerous plays on and off-Broadway.