In 2002, John wrote his autobiography entitled You Cannot Be Serious, a play on John's famous on-court line to umpires who missed calls.
John's brother Patrick was also a professional tennis player who followed his brother's footsteps into commentating matches.
John is of Irish-Catholic descent.
John's career prize money totaled more than $12.5 million.
John signed one of the first endorsement deals in tennis when he teamed up with Nike in 1978.
John joined the professional tennis circuit in 1978.
Throughout his tennis career, John garnered 77 singles titles including 7 Grand Slams.
John is left-handed.
In 1996, John McEnroe was named "Father of the Year" by the National Father's Day Committee.
In 1999, John McEnroe was inducted into the International Tennis Hall of Fame in Newport, RI.
In March 1980, at 21 years and 15 days, McEnroe became the then-youngest player in history to be ranked No 1.
McEnroe is the only player in history not to be granted an honorary membership to the All England Club when he first won Wimbledon in 1981.
In 1992, at the age of 33, John became the oldest men's player ever to win a Grand Slam title when he and Michael Stich of Germany captured the Wimbledon men's doubles championship.
McEnroe owns an art gallery in Manhattan.
John lists his height at 6'.
John attended Stanford University, though he did not graduate.
John's catchphrase on the court when questioning a call is "You cannot be serious!"
Since 1997, John has been married to singer/composer Patty Symth. The couple has had two children together.
Among John's nicknames are Johnny, Super Brat, and Johnny Mac.
McEnroe was the Wimbledon singles champ in 1981, 1983, and 1984.
From 1986 to 1994, John was married to actress Tatum O'Neal. After their divorce, John gained full custody of their three children.
John was born at the U.S. Air Force Hospital in Wiesbaden Air Force Base, Germany.
John is best known for his short temper on the tennis court when a call goes against him.
John came out of retirement to play doubles tennis at the February 13-19 tournament SAP Open in San Jose, California.
John won the U.S. Open singles championship four times: in 1979, 1980, 1981, and 1984.
John: (on having temper tantrums on the senior tour) It's not really what I'm feeling, I'm just doing it because it's the habit. I'd go out on the court and suddenly I'm doing something and I'd be like, 'Why am I doing this?'