
Acting
Gary Fred Merrill (August 2, 1915 – March 5, 1990) was an American film and television character actor whose credits included more than fifty feature films, a half-dozen mostly short-lived TV series, and dozens of television guest appearances.
Description above from the Wikipedia article Gary Merrill, licensed under CC-BY-SA, full list of contributors on Wikipedia.

Titans of Destruction: The Evolution of Giant Monster Movies
as Self - (archive footage)

Thieves
as Street Man

World of Darkness
as Dr. Thomas Madsen

For Liberty and Union
as Self - Narrator (voice)
The Zodiac Murders

Huckleberry Finn
as Pap

Pueblo
as Adm. Thomas E. Moorer

Murder and the Computer
as Gordon Craig

The Murderers

Earth II
as Walter Dietrich

The Littlest Hobo
as Willie Brogan · 2 ep.

The Seekers
as Capt. Hull · 2 ep.

Movin' On
1 ep.

Kung Fu
as Dan Hoyle · 1 ep.

Cannon
1 ep.

Young Dr. Kildare
as Dr. Leonard Gillespie · 24 ep.

Medical Center
1 ep.

Marcus Welby, M.D.
as Orlando 'Cord' Corday · 1 ep.

Hondo
2 ep.

The Time Tunnel
as Senator Leroy Clark · 1 ep.
The Incident
1967