He later starred in the NBC/CBS television crime drama In the Heat of the Night (1988–1995), where he played the role of police chief William "Bill" Gillespie.

In 1941, he enrolled at Wake Forest University in North Carolina but dropped out when the United States entered World War II.

He met Nancy Fields (born 1929), who later became his wife, when she was working as a makeup artist and lighting technician in a student-produced production of Our Town.

[2] After O'Connor's fiancée, Nancy Fields, graduated from the University of Montana in 1951 with degrees in drama and English, she sailed to Ireland to study at Trinity College Dublin and met Carroll, who was visiting his brother, Hugh.

[7] After acting in theatrical productions in Dublin and New York during the 1950s, O'Connor's breakthrough came when he was cast by director Burgess Meredith (assisted by John Astin) in a featured role in the Broadway adaptation of James Joyce's novel Ulysses.

These two parts led to other roles on such television series as The Americans, The Eleventh Hour, Bonanza, The Fugitive, The Wild Wild West, Armstrong Circle Theatre, The Outer Limits, The Great Adventure, The Man from U.N.C.L.E., Dr. Kildare, I Spy, That Girl, Premiere, Voyage to the Bottom of the Sea and Insight, and The Twilight Zone, among many others.

He was among the actors considered for the roles of the Skipper on Gilligan's Island and Dr. Smith in the TV show Lost in Space, and he was the visual template in the creation of Batman nemesis Rupert Thorne, a character who debuted at the height of All in the Family's success in Detective Comics No.

O'Connor appeared in a number of studio films in the 1960s and early 1970s, including Lonely Are the Brave (1962), Cleopatra (1963), In Harm's Way (1965), What Did You Do in the War, Daddy?

(1966), Warning Shot (1967), Point Blank (1967), The Devil's Brigade (1968), For Love of Ivy (1968), Death of a Gunfighter (1969), Marlowe (1969), Kelly's Heroes (1970) and Doctors' Wives (1971).

In the 1960s, O'Connor appeared in episodes of notable television series such as The Americans, The Untouchables, Naked City, Death Valley Days, Bonanza, The Defenders, The Outer Limits, The Fugitive, The Man from U.N.C.L.E., Voyage to the Bottom of the Sea, Ben Casey, Dr. Kildare, I Spy, The Wild Wild West, Mission: Impossible, The Time Tunnel, That Girl and Gunsmoke (1966 - "The Wrong Man"; S12E7).

O'Connor was living in Italy in 1968 when producer Norman Lear asked him to come to New York City and star in a series that he was creating for ABC titled Justice For All.

The show's writing was consistently left of center, but O'Connor, while his character held right-wing views, could also deftly skewer the liberal pieties of the day.

Racial issues, ethnicities, religions, sexuality, class, education, women's equality, gun control, politics, inflation, the Vietnam War, energy crisis, Watergate and other timely topics of the 1970s were addressed.

Like its British predecessor Till Death Us Do Part, the show lent dramatic social substance to the traditional sitcom format.

Stapleton decided she did not want to continue in the role, and in the second-season premiere, her character died of a stroke, leaving Archie to cope with the loss.

[17] While coping with his son's drug problem, O'Connor starred as Sparta, Mississippi, Police Chief Bill Gillespie, a tough veteran cop on In the Heat of the Night.

In 1989, while working on the set, O'Connor was hospitalized and underwent open heart surgery, which caused him to miss four episodes at the end of the second season.

[25][26] Following his son's death, O'Connor appeared in public service announcements for the Partnership for a Drug-Free America and spent the rest of his life working to raise awareness about drug addiction.

O'Connor also successfully lobbied the state of California to pass legislation allowing family members of an addicted person or anyone injured by a drug dealer's actions, including employers, to sue for reimbursement for medical treatment, rehabilitation costs and other economic and noneconomic damages.

[27][28] In an interview on CNN's Larry King Live soon after the verdict, O'Connor said that he would never be able to put his son's death behind him, saying: "I can't forget it.

[29] Among the cars O'Connor owned were a Rolls-Royce Silver Shadow sold to him by William Harrah, a Maserati 3500 GT, and a Dodge Challenger equipped with a 440-cubic inch V-8, which he drove during production of All in the Family.

In 1997, the O'Connors donated US$1 million (equivalent to $1,898,010 in 2023) to their alma mater to help match a challenge grant to the University of Montana from the National Endowment for the Humanities.

His funeral mass was celebrated at St. Paul the Apostle Catholic Church in Westwood, and was attended by All in the Family cast members Rob Reiner, Sally Struthers, and Danielle Brisebois, as well as producer Norman Lear.

[30] O'Connor's best friend Larry Hagman and his family attended the funeral, along with the surviving cast of In the Heat of the Night, including Alan Autry and Denise Nicholas.

O'Connor's body was buried at Westwood Village Memorial Park Cemetery with his son Hugh's cenotaph placed on his gravestone.

In honor of O'Connor's career, TV Land moved an entire weekend of programming to the next week and showed a continuous marathon of All in the Family.

During the commercial breaks, TV Land also showed interview footage of O'Connor and various All in the Family actors, producers with whom he had worked, and other associates.