He became involved with the United States Olympic Committee and helped to organize the 1984 Summer Olympics. Following this he became a track coach at Palm Springs High School. He was inducted into the USA Track & Field Hall of Fame in 2003.
Born in Harlem, New York, to Cuban parents, John Carlos was a gifted high school athlete and outstanding student who went on to study at East Texas State University on a full track-and-field scholarship. His victories in the 100- and 200-meter dash and as a member of the 4×400-meter relay helped lead ETSU to the 1967 Lone Star Conference Championship. After his first year, Carlos enrolled at San Jose State University where he was trained by future National Track & Field Hall of Fame coach, Lloyd (Bud) Winter.
Carlos was awarded an honorary doctorate from California State University in 2008. In 2012, he was awarded honorary doctorates from his alma maters Texas A&M University-Commerce (formerly East Texas State University) and San Jose State University.
At the 1968 Olympic Trials, Carlos won the 200-meter dash in 19.92 seconds, beating world-record holder Tommie Smith and surpassing his record by 0.3 seconds. Though the record was never ratified because the spike formation on Carlos' shoes ("brush spikes") was not accepted at the time, the race reinforced his status as a world-class sprinter.
Carlos became a founding member of the Olympic Project for Human Rights (OPHR), and originally advocated a boycott of the 1968 Mexico City Olympic Games unless four conditions were met: withdrawal of South Africa and Rhodesia from the games, restoration of Muhammad Ali's world heavyweight boxing title, Avery Brundage to step down as president of the IOC, and the hiring of more African-American assistant coaches. As the boycott failed to achieve support after the IOC withdrew invitations for South Africa and Rhodesia, he decided, together with Smith, to participate but to stage a protest in case he received a medal. Following his third-place finish behind fellow American Smith and Australian Peter Norman in the 200 at the Mexico Olympics, Carlos and Smith made headlines around the world by raising their black-gloved fists at the medal award ceremony. Both athletes wore black socks and no shoes on the podium to represent African-American poverty in the United States. In support, Peter Norman, the silver medalist who was a white athlete from Australia, participated in the protest by wearing an OPHR badge.
IOC president Avery Brundage deemed a political statement unfit for the apolitical, international forum the Olympic Games was supposed to be. In an immediate response to their actions, he ordered Smith and Carlos suspended from the U.S. team and banned from the Olympic Village. Many supporters, however, praised the men for their bravery. The men's gesture had lingering effects for all three athletes, the most serious of which were death threats against Carlos, Smith, and their families. Although it has been reported that Carlos and Smith were stripped of their medals, Carlos has indicated this is not true and his medal is with his mother.
Carlos had his greatest year in track and field in 1969, equaling the world 100-yard record of 9.1, winning the AAU 220-yard run, and leading San Jose State to its first NCAA championship with victories in the 100 and 220 and as a member of the 4×110-yard relay. He was featured on the cover of Track and Field News' May 1969 issue.
He was also the gold medalist at 200 meters at the 1967 Pan American Games in Winnipeg, Manitoba, Canada and set indoor world bests in the 60-yard dash (5.9) and the indoor 220-yard dash (21.2).
Following his track career, Carlos, a 15th round selection in the 1970 NFL Draft, tried professional football but a knee injury curtailed his tryout with the Philadelphia Eagles of the National Football League. He then went on to the Canadian Football League where he played one season for the Montreal Alouettes. Following his retirement from football, Carlos worked for Puma, the United States Olympic Committee, the Organising Committee of the 1984 Summer Olympics and the City of Los Angeles.
In 1985, Carlos became a counselor and in-school suspension supervisor, as well as the track and field coach, at Palm Springs High School in California. In 2003, he was elected to the National Track & Field Hall of Fame.
In 2005, a statue showing Carlos and Smith on the medal stand was constructed by political artist Rigo 23 and dedicated on the campus of San Jose State University.
In 2006, John Carlos delivered a eulogy at Peter Norman's funeral and was also a pallbearer at the ceremony.
In 2007, John Carlos was honored at the Trumpet Awards in Las Vegas, Nevada.
Carlos is the godfather of Chicago White Sox General Manager Kenny Williams. Carlos and Williams' father ran track together in college.
In April 2008, Carlos was a torch-bearer for the Human Rights Torch, which ran in parallel to the 2008 Summer Olympics torch relay and focusing attention on China's human rights record.
On July 16, 2008, John Carlos and Tommie Smith accepted the Arthur Ashe Award for Courage for their salute, at the 2008 ESPY Awards held at NOKIA Theatre L.A. LIVE in Los Angeles, California.
On October 10, 2011, Carlos spoke and raised his fist at Occupy Wall Street. He said: "Today I am here for you. Why? Because I am you. We're here forty-three years later because there's a fight still to be won. This day is not for us but for our children to come." The following day he appeared on MSNBC and on Current TV's Countdown with Keith Olbermann.
An airbrush mural of the trio on podium exists in the Sydney suburb of Newtown. Silvio Offria, who allowed an artist known only as "Donald" to paint the mural on his house, said Norman came to Newtown to see the mural before he died in 2006, "He came and had his photo taken, he was very happy."