Robert Martin Culp (August 16, 1930 - March 24, 2010) was an American actor and director. He was the voice actor for Wallace Breen in Half-Life 2. Sound clips from the latter were reused for Half-Life 2: Episode One.
Actor, scriptwriter, and director, Culp was widely known for his work in television. He earned an international reputation for his role as Kelly Robinson on I Spy (1965–1968), the espionage series, where he and co-star Bill Cosby played a pair of secret agents.
Culp died on the morning of March 24, 2010 after suffering a heart attack outside his home in Los Angeles, at the age of 79. Plans by Valve about Wallace Breen in the future of the series are currently unknown to date.