McCord was born Kent Franklin McWhirter in Los Angeles, California. Using the stage name Kent McCord, he first appeared on television in 1962 on ABC‘s The Adventures of Ozzie & Harriet. He became a close friend of Ricky Nelson and made a total of 19 appearances on the program over the next few years. He also landed small parts in three Elvis Presley films. He also appeared as a motorcycle courier in a McHale’s Navy episode entiled “Monkey Business 007” under the name Kent McWhirter.
After working in a variety of secondary roles, he got his big break in 1968 when he was given a lead role next to Martin Milner as rookie LAPD police officer James A. “Jim” Reed on Adam-12, a police drama television series created by Jack Webb. The popular show ran on NBC from 1968 to 1975 and made McCord a household name. In Jack Webb’s Dragnet 1967, he made a guest appearance as a novice undercover officer Paul Culver. Also as a uniformed officer in episode 2, “The Big Explosion”, credited as Kent McWhirter.
In 1972, McCord was elected to the National Board of Directors of the Screen Actors Guild and served on the Board for 11 years. He served as 1st National Vice President and served on the National Board of Directors In 1980, McCord played the lead character Troy on the short-lived series Galactica 1980. He was then pegged to play Jack Webb’s partner (his Officer Jim Reed character from “Adam-12”), in another revival of Dragnet, but the project ended with Webb’s death in 1982. Also in 1982, McCord had a role as Dave Unger, a navigator on the “Lunar Shuttle” Mayflower in that year’s big summer comedy Airplane II: The Sequel, McCord’s only known comedy role. McCord re-teamed with Martin Milner, his co-star in “Adam-12”, in the cable TV-movie Nashville Beat (1990), originally shown on the now defunct The Nashville Network. In this story that McCord partially wrote, he played an LAPD detective who teams up with his old partner (Milner) in Nashville. In 1990 McCord appeared in the film Predator 2 as Captain Pilgrim. From 1994 through 1995, McCord played the recurring role of Scott Keller on seaQuest DSV.
In 1999 he was introduced to a new generation of fans as a semi-regular guest star on the science fiction television cult hit, Farscape. He played two versions (one human and one alien appearing in the physical form of the human) of the same character, Jack Crichton. In 2003, he ran for President of the Screen Actors Guild but lost to Melissa Gilbert by a margin of 42% to her 50%.