Peter Mackenzie

Peter Mackenzie (born Peter Cook; January 19, 1961) is an American actor. He co-starred in films Good Morning, Vietnam (1987), Torch Song Trilogy (1988), Lorenzo's Oil (1992) and Trumbo (2015). He is also known for his television roles on Herman's Head (1991–1994), ER (2002), Gilmore Girls (2006), Grey's Anatomy (2009), How I Met Your Mother (2011) and Black-ish (2014–).

Mackenzie lives in Los Angeles with his wife, a writer. They have three adult children.

In 2014, Mackenzie installed a small curbside book exchange on public land near his home which he called "The Tenn-Mann Library". Popular in the neighborhood, it was cited for a local ordinance violation after an anonymous complaint.

Mackenzie was the brother of screenwriter Douglas Cook, who died in 2015.