Gaylord was born in Van Nuys, California, the son of Fred and Linda Gaylord. His family is Jewish. He made his first U.S. National team in gymnastics in 1980 and continued to retain his place on the team for the next five years. While attending UCLA as a history major on scholarship, he won the All-Around in the 1983 and 1984 USA Gymnastics National Championships, and the 1984 NCAA Men's Gymnastics Championship. He then qualified for the Olympic Games during the Olympic trials held from June 1–3, 1984 in Jacksonville Florida. Two of the moves in his arsenal going into the Games were invented by and named for him—the Gaylord flip and the Gaylord II.

In the 1984 Summer Olympic Games, Gaylord led the gold-medal-winning U.S. men's gymnastics team, becoming the first American Gymnast to score a perfect 10.00 in the Olympics. He also won the silver medal in vault, the bronze in parallel bars and the bronze in the rings. In addition to his individual accolades, Gaylord led the US men's gymnastics team to a gold medal in the team competition for the first and only time in Olympics history. The moment was heralded as a significant upset over the teams from China and Japan. After the 1984 Olympics he and his fellow Olympic Gymnasts went on a six-month promotional tour across the US, selling out arenas in about two dozen American cities. He also wrote his first book during this period, centering on using gymnastics exercises to train. He was also named by President Ronald Reagan as a member of the President's Council on Physical Fitness and Sports in November 1985.

Gaylord has appeared in several movies and TV shows. Most notably, he performed as a stunt double for Chris O'Donnell (as Robin) in the 1995 movie Batman Forever, and played the lead in American Anthem (1986), opposite Actress Janet Jones. The latter movie, in which Gaylord played a Gymnast training for the Olympics, has been noted as an inspiration to Future generations of Olympic Gymnasts. He was also a frequent guest star on Hollywood Squares, and appeared in advertisements for Diet Coke, Nike, Vidal Sassoon, Soloflex, Levi's, and Texaco. Over the years Gaylord has also remained an ambassador to the sport of gymnastics, serving as a commentator for NBC and Fox Sports during televised gymnastics events, as well as developing several nationally televised fitness programs and products. He currently works as a financial advisor at Morgan Stanley Smith Barney.

In June 2007, Gaylord was named the seventh best US Gymnast of all time by Yahoo Sports. He was also named to the UCLA Hall of Fame in 1995, the US Olympic Hall of Fame in 2006, and the International Jewish Sports Hall of Fame in 2009. He has also been an advocate for child allergy awareness.