John C. McGinley, sometimes credited as John McGinley, has had a prolific career, primarily as a supporting character actor. He came to fame in Oliver Stone's Platoon in 1986, and went on to work on four other Stone productions.

McGinley is known for his cynical, wacky, sometimes sinister character portayals. He owns a stake in one of Billy Gilroy's New York SoHo bistros along with fellow actor Willem Dafoe. His co-workers call him "Johnny C."

McGinley was raised in Millburn, New Jersey, and attended Millburn High School. He studied acting at Syracuse University, and later at New York University's Tisch School of the Arts. Upon completing his education, McGinley did a variety of different work, including on- and off-Broadway productions, and a two year stint on the soap opera Another World.

While working as John Turturro's understudy in John Patrick Shanley's 1984 production of Danny and the Deep Blue Sea he was noticed by a casting scout, which led to an audition for the role of Sergeant Red O'Neill in the Oscar-winning Platoon, although his first movie role was Alan Alda's Sweet Liberty (1986).

That was followed the next year with Wall Street (1987), and again the next with Talk Radio (1988). McGinley showcased his screenwriting talents with 1990's Suffering Bastards, in which he also co-starred.

He worked almost continually throughout the 1990s on a swathe of movies, most notably in David Fincher's Se7en (1995), The Rock and Mike Judge's classic Office Space (1999) where he improvised several takes about his character's affinity for Michael Bolton. Less notable was McGinley's role in the widely disparaged Highlander II: The Quickening (1991).

McGinley received critical acclaim for his starring role in Dean Koontz's suspense drama, Intensity (1997). The two-part miniseries became Fox's highest-rated miniseries. He joined forces with Koontz and Fox once more for Sole Survivor in 2000.

In 2001, McGinley began his acclaimed work as a regular on the NBC sitcom Scrubs as the acerbic Dr. Perry Cox. According to the IMDb, he originally took the role to be closer to his son Max, who was born in 1997 with Down syndrome. McGinley currently serves as the national spokesperson for the National Down Syndrome Society's annual Buddy Walks and wears a "Buddy Walk" bracelet on Scrubs.

McGinley has done some voiceover work on animated television series, including the superhero The Atom on several episodes of Justice League Unlimited and a guest appearance as "The White Shadow," the secret government agent overseeing Huey Freeman on The Boondocks.