Mike Kellin was born on April 26, 1922. Mike was the son of an English immigrant clothier and then he decided that he wanted to become an actor in the second grade after watching a school production of A Christmas Carol. After school he brieflt attended three colleges before serving in the Navy in World War II. He flunked out of Yale Drama School and headed to New York where he studied acting under Lee Strassberg, Sanford Meisner and Stella Adler. Kellin then had his big break by playing a role of the abrasive sergeant in the 1949 Broadaway comedy production of At War with the Army and would reprise his role in the 1950 motion picture version which starred Martin and Lewis. He also went on to win the Tony award for his performance in the 1956 production of Rogers and Hammerstein's musical production of Pipe Dream. He also had regular roles in the TV shows Bonino and Honestly Celeste! He was noted for his role as Chief Mate Jack MacCarthy in the motion picture comedy The Wackiest Ship in the Army starring Jack Lemmon and Ricky Nelson which led to a short-lived TV series as Kellin reprised his role for the series. He also had supporting roles in many other film's mainly playing tough guy roles like in Hell is for Heroes (Starring Steve McQueen), The Boston Strangler (Starring Tony Curtis, Henry Fonda and George Kennedy), The People Next Door, Fools' Parade (Starring James Stewart, George Kennedy and Anne Baxter), The Last Porno Flick, Freebie and the Bean (Starring Alan Arkin, James Caan and Loretta Swit) and Next Stop Greenwich Village (Starring Shelly Winters, Lois Smith and Christopher Walken). He also guest starred in many epsiodes of the Alfred Hitchcock Hour and an episode of the Twilight Zone.

He landed a supporting role in 1976 as a Deputy Police Officer in his first horror flick by Larry Cohen titled God Told Me To of a series of motiveless murders committed by various New York residents. The only consistent pattern to the crimes involves the perpetrators calm admissions of guilt, explaining, "God told me to." Mike's character with Tony LeBianco (Who is the head detective named Lt. Peter J. Nicholas) are increasingly troubled by the evidence of a Christ-like figure named Bernard Phillips (Richard Lynch) who appeared to each of the killers and can't seem to shake the feeling that his own fate is somewhat linked to this mysterious being. As they comes closer to the truth, his worst fears are confirmed.

In 1981 he had another supporting role in his second horror flick which was a summer camp slasher film titled Just Before Dawn which was almost a combination of the films Friday the 13th, Texas Chainsaw Massacre and The Hills Have Eyes. In this one, Mike plays a drunk named Ty who goes on a mountain hike with his nephew. They go to an abandoned church house and a hulking mountain killer slays his nephew and destroys his vehicle. Ty runs away and tries to warn a young group of people that travel up to the mountains of a property that they bought warning them about demons but they think he's crazy. He later notifies the forest ranger named Roy McLean (George Kennedy) about demons in the mountains after Roy sees him drinking out of his horses drinking tub.

When cancer struck him, he starred in his last film which was another slasher camp horror flick in 1983 titled Sleepaway Camp as the lead role named Mel who was a crazed an obnoxious person. Two kids go to his camp known as Camp Arawak and one of the kids is being micked and tormented by bullies. The bullies are murdered for their nasty deeds and Mel tries to cover it up saying that they were just terrible accidents to keep his reputation good at his campground. The writer/director Robert Hiltzik was a graduate from film school while making this cheesy horror flick which years later became a cult classic as it was an independent film and said he was fortunate to have a name like him in his film and helped it get off the ground because of him. While the flick was wrapping up in it's in post-production run, Mike sadly passed away from cancer on August 26, 1983 in Nyack, New York and he sadly never had a chance to see it when the film hit the theatre's on November 18, 1983. He was a remembered name in the film nevertheless.