Connors was born Kevin Joseph Connors in Brooklyn, New York to Allan, a longshoreman, and Marcella Connors, immigrants from the Dominion of Newfoundland (now part of Canada). Connors was raised Roman Catholic and served as an altar boy at the Basilica of Our Lady of Perpetual Help in Brooklyn. Connors had one sibling, a sister, Gloria.  Connors did not like his first name and was seeking another one. He tried out “Lefty” and “Stretch” before settling on “Chuck”, because while playing first base, he would always yell, “Chuck it to me, baby, chuck it to me!” to the pitcher. The rest of his teammates and fans soon caught on and the name stuck. He loved the Brooklyn Dodgers despite their losing record during the 1930s, and hoped to someday join the team himself. Connors’ athletic abilities earned him scholarships to the Adelphi Academy (from which he graduated in 1939) and Seton Hall University in South Orange, New Jersey, which he left after two years.  During World War II (1939–45), he enlisted in the Army at Fort Knox, Kentucky, and spent most of the war as a tank-warfare instructor at Fort Campbell, Kentucky and later at West Point, New York.  During his Army service, Connors moonlighted as a professional basketball player, joining the Rochester Royals and helping to lead them to the 1946 National Basketball League championship. Following his military discharge in 1946, he joined the newly formed Boston Celtics of the Basketball Association of America.  Connors left the team for spring training with Major League Baseball’s Brooklyn Dodgers. He played for numerous minor league teams before joining the Dodgers in 1949, for whom he played in only one game. He joined the Chicago Cubs in 1951, playing in 66 games as a first baseman and occasional pinch hitter. In 1952, he was sent to the minor leagues again to play for the Cubs’ top farm team, the Los Angeles Angels.  He was drafted by the NFL’s Chicago Bears, but never suited up for the team. He is also credited as the first professional basketball player to break a backboard. During warmups in the first-ever Boston Celtics game on November 5, 1946 at Boston Arena, Connors took a shot that caught the front of the rim and shattered an improperly installed glass backboard.  In 1966, Connors played an off-field role by helping to end the celebrated holdout by Los Angeles Dodgers pitchers Don Drysdale and Sandy Koufax when he acted as an intermediary during negotiations between the team and the players. Connors can be seen in the Associated Press photo with Drysdale, Koufax and Dodgers general manager Buzzie Bavasi announcing the pitchers’ new contracts.

Connors realized that he would not make a career in professional sports, so he decided to pursue an acting career. Playing baseball near Hollywood proved fortunate, as he was spotted by an MGM casting director and subsequently signed for the 1952 Tracy-Hepburn film Pat and Mike. In 1953, he starred opposite Burt Lancaster as a rebellious Marine private in the film South Sea Woman and Trouble Along the Way opposite John Wayne as a football coach.  Connors had a rare comedic role in a 1955 episode (“Flight to the North”) of The Adventures of Superman. He portrayed Sylvester J. Superman, a lanky rustic yokel who shared the same name as the title character of the series.  Connors was cast as Lou Brissie, a former professional baseball player wounded during World War II, in the 1956 episode “The Comeback” of the religion anthology series Crossroads. Don DeFore portrayed the Reverend C. E. “Stoney” Jackson, who offered the spiritual insight to assist Brissie’s recovery so that he could return to the game. Grant Withers was cast as Coach Whitey Martin; Crossroads regular Robert Carson also played a coach in this episode. Edd Byrnes, Rhys Williams, and Robert Fuller played former soldiers. X Brands is cast as a baseball player.  In 1957, Connors was cast in the Walt Disney film Old Yeller in the role of Burn Sanderson. That same year, he co-starred in The Hired Gun.  Connors acted in feature films including The Big Country, Move Over Darling with Doris Day and James Garner, Soylent Green with Charlton Heston, and Airplane II: The Sequel.  He also became a lovable television character actor, guest-starring in dozens of shows. His guest-starring debut was on an episode of NBC’s Dear Phoebe. He played in two episodes, one as the bandit Sam Bass, on Dale Robertson’s NBC western Tales of Wells Fargo.  Other television appearances were on Hey, Jeannie!, The Loretta Young Show, Schlitz Playhouse, Screen Directors Playhouse, Four Star Playhouse, Matinee Theatre, Cavalcade of America, Gunsmoke, The Gale Storm Show, West Point, The Millionaire, General Electric Theater hosted by Ronald W. Reagan, Wagon Train, The Restless Gun, Murder, She Wrote, Date with the Angels, The DuPont Show with June Allyson, The Virginian, Night Gallery, Here’s Lucy and many others.

Connors beat 40 other actors for the lead on The Rifleman, portraying Lucas McCain, a widowed rancher known for his skill with a customized Winchester rifle. This ABC Western series, which aired from 1958 to 1963, was also the first show to feature a widowed father raising a young child. Connors said in a 1959 interview with TV Guide that the producers of Four Star Television (Dick Powell, Charles Boyer, Ida Lupino and David Niven) must have been looking at 40–50 thirty-something males. At the time, the producers offered a certain amount of money to do 39 episodes for the 1958–59 season. The offer turned out to be less than Connors was making doing freelance acting, so he turned it down. A few days later, the producers of The Rifleman took their own children to watch Old Yeller in which Connors played a strong father figure. After the producers watched him in the movie, they decided they should cast Connors in the role of Lucas McCain and make him a better offer, including a five-percent ownership of the show.  The Rifleman was an immediate hit, ranking No. 4 in the Nielsen ratings in 1958–59, behind three other Westerns – Gunsmoke, Wagon Train, and Have Gun – Will Travel. Johnny Crawford, a former Mousketeer, baseball fan and Western buff, beat 40 other young stars to play the role of Lucas’s son, Mark. Crawford remained on the series from 1958 until its cancellation in 1963. The Rifleman landed high in the Nielsen ratings until the last season in 1962–63, when it was opposite the highly rated return to television of Lucille Ball on The Lucy Show and ratings began to drop. The show was cancelled in 1963 after five seasons and 168 episodes.

Johnny Crawford said of his relationship with Connors: “I was very fond of Chuck, and we were very good friends right from the start. I admired him tremendously.” Crawford also said about the same sport that Connors had played: “I was a big baseball fan when we started the show, and when I found out that Chuck had been a professional baseball player, I was especially in awe of him. I would bring my baseball and a bat and a couple of gloves whenever we went on location, and at lunchtime I would get a baseball game going, hoping that Chuck would join us. And he did, but after he came to bat, we would always have trouble finding the ball. It would be out in the brush somewhere or in a ravine, and so that would end the game.” Crawford stayed in touch with Connors until his death in 1992. “We remained friends throughout the rest of his life. He was always interested in what I was doing and ready with advice, and anxious to help in any way that he could … He was a great guy, a lot of fun, great sense of humor, bigger than life, and he absolutely loved people. He was very gregarious and friendly, and not at all bashful … I learned a great deal from him about acting, and he was a tremendous influence on me. He was just my hero.” He and Connors reprised their roles as the McCains in a television western movie, The Gambler Returns: The Luck of the Draw.

In 1963, Connors appeared in the film Flipper. He also appeared opposite James Garner and Doris Day in the comedy Move Over, Darling.  As Connors was strongly typecast for playing the firearmed rancher-turned-single-father, he then starred in several short-lived series, including: ABC’s Arrest and Trial, featuring two young actors Ben Gazzara and Don Galloway, NBC’s post-Civil War-era series Branded (1965–1966) and the 1967–1968 ABC series Cowboy in Africa, alongside British actor Ronald Howard and Tom Nardini. Connors guest-starred in a last-season episode of Night Gallery titled “The Ring With the Red Velvet Ropes”. In 1973 and 1974 he hosted a television series called Thrill Seekers.  He had a key role against type as a slave owner in the 1977 miniseries Roots, and was nominated for an Emmy Award for his performance.  Connors hosted a number of episodes of Family Theater on the Mutual Radio Network. This series was aimed at promoting prayer as a path to world peace and stronger families, with the motto, “The family which prays together stays together.”  In 1983, Connors joined Sam Elliott and Cybill Shepherd in the short-lived NBC series The Yellow Rose, about a modern Texas ranching family. In 1985, he guest-starred as “King Powers” in the ABC TV series Spenser: For Hire, starring Robert Urich. In 1987, he co-starred in the Fox series Werewolf, as drifter Janos Skorzeny. In 1988, he guest-starred as “Gideon” in the TV series Paradise, starring Lee Horsley.  In 1991, Connors was inducted into the Western Performers Hall of Fame at the National Cowboy & Western Heritage Museum in Oklahoma City.

Connors was married three times. He met his first wife, Elizabeth Jane Riddell Connors, at one of his baseball games, and married her on October 1, 1948. They had four sons, Michael (born 1950), Jeffrey (1952-2014), Steven (born 1953), Kevin (1956–2005), but divorced in 1961.  Connors married Kamala Devi (1963) the year after co-starring with her in Geronimo. She also acted with Connors in Branded, Broken Sabre, and Cowboy in Africa. They were divorced in 1973.  Connors played in Soylent Green (1973), as Tab Fielding, and Faith Quabius played an attendant. They were married in 1977 and divorced in 1979.  Connors was a supporter of the Republican Party and attended several fundraisers for campaigns for U.S. President Richard M. Nixon.  Connors was introduced to Secretary General Leonid Brezhnev of the former Soviet Union at a party given by Nixon at the Western White House in San Clemente, California, in June 1973. Connors presented Brezhnev with a pair of Colt Single Action Army “Six-Shooters” (revolvers) which Brezhnev liked greatly. Upon boarding his airplane bound for Moscow, Brezhnev noticed Connors in the crowd and went back to him to shake hands, and jokingly jumped up into Connors’ towering hug. The Rifleman was one of the few American shows allowed on Russian television at that time; that was because it was Brezhnev’s favorite. Connors and Brezhnev got along so well that Connors traveled to the Soviet Union in December 1973. In 1982, Connors expressed an interest in traveling to the Soviet Union for Brezhnev’s funeral, but the U.S. government would not allow him to be part of the official delegation. Coincidentally, Connors and Brezhnev died on the same day, ten years apart.

Connors had started smoking in 1940. For many years he smoked three packs of Camel cigarettes a day until he quit the habit in the mid-1970s, though he occasionally resumed smoking afterwards. He died on November 10, 1992 at Cedars-Sinai Medical Center in Los Angeles at the age of 71 of pneumonia stemming from lung cancer. At the time of his death, his companion was Rose Mary Grumley. He was interred in the San Fernando Mission Cemetery in Los Angeles.