Deathlok (also referred to as Deathlok the Demolisher) is a fictional cyborg published by Marvel Comics. He first appeared in Astonishing Tales #25 (Aug. 1974), and was created by Rich Buckler and Doug Moench. At least three subsequent Marvel characters have used the "Deathlok" identity since then.

Although initially announced as the new lead feature for Marvel's Worlds Unknown comic, under the title "Cyborg," the first Deathlok series ran in Astonishing Tales #25-36 (cover-dated Aug. 1974 - July 1976). This initial version of the character, Luther Manning, later guest-starred with Spider-Man in Marvel Team-Up #46 (June 1976), and the story from the cancelled Astonishing Tales comics was finished in Marvel Spotlight #33 (April 1977).

Deathlok subsequently appeared with the Thing, a member of the superhero team the Fantastic Four, in Marvel Two-in-One #26, 27, 28, 34 and #54, although one appearance was actually a robot and not the genuine Deathlok. The Luther Manning Deathlok then appeared in Captain America #286-288 (Oct.-Dec. 1983).