Matthew Arkin is an American film, television, and theatre actor, best known for City Island, Margot at the Wedding, Liar Liar, and An Unmarried Woman. Other film credits include Veronica Mars, Snatched, The Flying Scissors, Second Best, and Death to Smoochy. 

Television credits include Dr. Norton on ABC's All My Children, Dr. Thompson on FX's Rescue Me, and Paul Bernard on A&E's 100 Centre Street.

Theatre credits include his Broadway debut as Lucas in Laughter on the 23rd Floor (Richard Rodgers Theatre), Reggie Ellis in Losing Louie (Biltmore Theatre), and Ben Silverman in The Sunshine Boys (Lyceum Theatre); Off-Broadway, as Mr. Kenyon/Uncle Paul in Indian Blood (59E59 Theater), Ben Hecht in Moonlight and Magnolias (N.Y. City Center), Michael in Rounding Third (John Houseman Theatre), Gabe in Dinner with Friends (Variety Arts Theatre), Walter in You Should Be So Lucky (Westside Theatre), and Jamey in The King of Carpets (Jewish Repertory Theatre).