Dennis Dugan (born September 5, 1946) is an American actor and film director.

Dugan did quite well for himself trading out a bumbling-but-huggable screen image. On screen at least since 1972, Dugan established his screen persona in brief doses in such films as Harry and Walter Go To New York (1976) and Norman Is That You (1976). In 1979, he was ideally cast as the time-displaced hero in Unidentified Flying Oddball, Disney's updated remake of A Connecticut Yankee in King Arthur's Court. Television has always a welcome mat for Dugan: his first notable appearance was in the Columbo episode Last Salute To The Commodore, as a young police officer mentioned to be 29, just Dugan's real age at the time. Then he was the star of the short-lived series Richie Brockelman, Private Eye (1977) (a character who originated in a telemovie and then made guest appearances on The Rockford Files before getting his own show), Empire (1984) and Shadow Chasers (1984), and was a semi-regular as an erstwhile "caped crusader" on Hill Street Blues (when Dugan's character was killed off, many disconsolate viewers wrote in to warn that they would never watch the show again). Dugan's films credits of the 1980s have been plentiful if not distinguished, including Can't Buy Me Love (1987) and The New Adventures of Pippi Longstocking (1988).

Dugan has also made a career as a television and film director, and appears in cameo parts in many of his films. Films directed by Dennis Dugan include the 1990 comedy Problem Child (with Dugan appearing as an All-American dad), the 2001 comedy Saving Silverman (where Dugan plays a football referee), the 2003 comedy National Security, and the 1996 and 1999 Adam Sandler comedies Happy Gilmore (in which Dugan plays Doug Thompson, the golf tour supervisor) and Big Daddy (with Dugan as a man who reluctantly gives candy to a trick-or-treating Julian). Dugan has directed episodes of such television series as Moonlighting, Ally McBeal, and NYPD Blue.

Dugan directed The Benchwarmers, a comedy released on April 7, 2006. The film, co-written by Adam Sandler, is about trio of guys who try to make up for missed opportunities in childhood by forming a three-player baseball team to compete against standard Little League squads. Dugan himself has a bit part as Coach Bellows. Dugan directed the controversial 2007 film I Now Pronounce You Chuck and Larry.

Graduated from Wheaton Central High School in 1962 or 1963.

Often collaborates with Adam Sandler (I).

Ex-brother-in-law of Dick Van Patten.