O'Brian was born Hugh Charles Krampe in Rochester, New York, the son of Hugh John Krampe, a career United States Marine Corps officer, and his wife Edith Krampe. He attended New Trier High School in Winnetka, Illinois (as did Rock Hudson, Charlton Heston, Ann-Margret and many other future stars) and later Kemper Military School in Boonville, Missouri. He lettered in football, basketball, wrestling, and track. O'Brian dropped out of the University of Cincinnati after one semester to enlist in the Marine Corps during World War II. Only 17, he became the youngest Marine drill instructor.
After World War II, O'Brian moved to Los Angeles to study at UCLA. He was discovered on the stage by Ida Lupino who signed him to a film she was directing Never Fear that led to a contract with Universal Pictures.
He was chosen to portray legendary lawman Wyatt Earp on ABC, The Life and Legend of Wyatt Earp which debuted in 1955. Alongside Gunsmoke, which debuted the same year, these shows spearheaded the "adult western" TV genre, where the emphasis is on character development as opposed to mere moral sermonizing. It soon became one of the top-rated shows on television. During its seven-year run, Wyatt Earp consistently placed in the top 10 in the United States. He also appeared regularly on other programs in the 1960s, including Jack Palance's ABC circus drama, The Greatest Show on Earth, and as a 'guest attorney' in an episode of Perry Mason when its star Raymond Burr was sidelined for a spell after minor emergency surgery. He was a guest celebrity panelist on the popular CBS prime-time programs Password and What's My Line? and even served as a mystery guest on three occasions.
The actor made a number of motion pictures, among them The Lawless Breed (1953), There's No Business Like Show Business (1954), White Feather (1955), Come Fly with Me (1963), Love Has Many Faces (1965), In Harm's Way (1965) and Ambush Bay (1966). While on stage, Elvis Presley introduced O'Brian from the audience at the singer's April 1, 1975 performance at the Las Vegas Hilton, as captured in the imported live CD release "April Fool's Dinner." O'Brian was a featured star in the 1977 two-hour premiere of television's Fantasy Island. He is the last man that John Wayne ever killed on the screen in Wayne's final movie The Shootist (1976). O'Brian was a good friend of the Duke and said he considers this a great honor. O'Brian appeared in fight scenes with a Bruce Lee lookalike in Lee's last film Game of Death.
O'Brian recreated his Wyatt Earp role for two 1990s projects, Guns of Paradise (1990) and The Gambler Returns: The Luck of the Draw (1991) with fellow actor Gene Barry doing likewise as lawman Bat Masterson for each. He also had a small role in the Danny DeVito/Arnold Schwarzenegger 1988 film comedy Twins, as one of several men who had "donated" the DNA that later became the "twins." In the film, Schwarzenegger thought he'd found his "father," when he met Hugh O'Brian's character.
For his contribution to the television industry, Hugh O'Brian has a star on the Hollywood Walk of Fame at 6613½ Hollywood Blvd. In 1992, he was inducted into the Western Performers Hall of Fame at the National Cowboy & Western Heritage Museum in Oklahoma City, Oklahoma.
On June 25, 2006, O'Brian, at the age of 81, married for the first time. His wife is the former Virginia Barber (born ca. 1952). The ceremony was held at Forest Lawn Memorial Park, with the Reverend Robert Schuller, pastor of the Crystal Cathedral in Garden Grove, officiating. The couple was serenaded by close friend Debbie Reynolds.
Hugh O'Brian has dedicated much of his life to the Hugh O'Brian Youth Leadership (HOBY). HOBY is a non-profit youth leadership development program that empowers 10,000 sophomores annually through its over 70 leadership programs in all 50 states and 20 countries. Since its inception in 1958, over 355,000 young people have been inspired by HOBY.
One high school sophomore from every high school in the United States, referred to as an “ambassador,” is welcome to attend a state or regional HOBY seminar. From each of those seminars, students (number based on population) are offered the opportunity to attend the World Leadership Conference (WLC) held at George Washington University in Washington, D.C. In 2008, over 500 ambassadors attended from all 50 states and 20 countries.
The concept for HOBY was inspired in 1958 by a nine-day visit O’Brian had with famed humanitarian Dr. Albert Schweitzer in Africa. Dr. Schweitzer believed "the most important thing in education is to teach young people to think for themselves."
Hugh O’Brian’s message to young people is “Freedom to Choose” Here is his brief speech on this topic: "I do NOT believe we are all born equal. Created equal in the eyes of God, yes, but physical and emotional differences, parental guidelines, varying environments, being in the right place at the right time, all play a role in enhancing or limiting an individual's development. But I DO believe every man and woman, if given the opportunity and encouragement to recognize their potential, regardless of background, has the freedom to choose in our world. Will an individual be a taker or a giver in life? Will that person be satisfied merely to exist or seek a meaningful purpose? Will he or she dare to dream the impossible dream?
"I believe every person is created as the steward of his or her own destiny with great power for a specific purpose, to share with others, through service, a reverence for life in a spirit of love."