As a contract player for Warner Brothers, Peter Brown appeared in the films Red Nightmare and Darby’s Rangers. Though his role in Onionhead was cut from the completed film, the producer Julius Schermer hired him for Deputy Johnny McKay in Lawman, an important part that lasted from 1958 to 1962. Brown was the last surviving member of the series. Brown also appeared in the 1962 film, Merrill’s Marauders. Brown appeared in dozens of other television shows and did several crossovers with other western series as Johnny McKay, including Maverick, in the 1961 episode “Hadley’s Hunters,” featuring Jack Kelly as Bart Maverick, along with a host of characters from other Warner Brothers. westerns, including Cheyenne (Clint Walker), Bronco (Ty Hardin), and Sugarfoot (Will Hutchins). In the Cheyenne episode “Renegades” (1958), Brown at twenty-two was cast as 17-year-old Jed Wayne, who enlists in the United States Army after his father is killed in an attack by Comanche renegades. Olive Sturgess played Kathy Donovan, who takes an interest in young Wayne and is the daughter of the fort commander, Colonel Ralph Donovan (Bartlett Robinson), who distrusts the Indians. The episode also focuses on the spirit and endurance of Wayne’s mortally lame horse and the wisdom of the Comanche chief, Little Elk (Steve Darrell).

Peter Brown twice guest-starred in another ABC/WB western, Colt .45, with Wayde Preston. He appeared as Dave with Andrew Duggan and Bob Steele, who were cast as Jim Rexford and Sergeant Granger respectively in “The Peacemaker” or “Judgment Day”, the series premiere in 1957. Thereafter that same season, he was cast as Jimmy Benedict opposite Charles Bronson as the outlaw Danny Arnold in the episode “Young Gun”. In the story line, Benedict, who wants to make a name for himself, challenges Arnold to a gunfight. After his contract with Warner Brothers lapsed, Brown made two films for Walt Disney Studios, including Summer Magic with Hayley Mills and Burl Ives. He appeared in other television series too, such as Redigo, starring Richard Egan as a New Mexico rancher. He contracted to Universal Pictures for the 1965 NBC western television series Laredo, set on the Mexican border in and about Laredo, Texas. Brown appeared in the pilot for Police Woman, starring Angie Dickinson.

Peter Brown began the 1970s in exploitation films such as Foxy Brown, Chrome and Hot Leather, and Rape Squad and many soap operas. On Days of Our Lives, he played Dr. Greg Peters from 1972-1979 who was involved in a romance with Amanda Howard (Mary Frann). He was Laurie Brooks’ attorney, Robert Laurence, on The Young and the Restless (1981-1982) when she was on trial for the murder of her former mother-in-law, Vanessa Prentiss. After the storyline ended, he romanced Laurie’s sister, Leslie Brooks, but that ended when his wife Claire came out of a long comatose state. He would return briefly to “Y&R” in between soap stints in the late 1980s. Peter replaced John Shearin as Roger Forbes on Loving during its early days, but was written out after only a couple of months. From 1986-1987, he played Charles Sanders, former ambassador to Mendora on One Life to Live whose family briefly dominated the front-burner of the soap. His character memorably had a heart attack and died on the evening of his wedding to Lee Halpern. Later on, he played Blake Hayes on The Bold and the Beautiful, the ex-husband of Dr. Taylor Forrester. He continued to perform in various American television guest-star roles. Peter Brown died on March 21, 2016 in Phoenix, Arizona, from complications of Parkinson’s disease, aged 80.