Myers was born and raised in Scarborough, Ontario, Canada, the son of Alice E. (née Hind; b. 1926), an office supervisor who was formerly in the Royal Air Force, and Eric Myers (died in 1991), who worked in the insurance business and previously was a Royal Engineer in the British Army.^[1][2] Both of his parents are from Liverpool. He has two older brothers, Peter and Paul Myers, who is an indie rock singer-songwriter, broadcaster and author. Myers is of English, Scottish, and Irish ancestry,^[3] and was raised Protestant.^[4] He attended Sir John A. Macdonald Collegiate Institute but then changed schools and went to Stephen Leacock Collegiate Institute in Scarborough, Ontario. Myers also attended Second City at the age of 19. He began working in commercials at age eight, and at ten he made a commercial for British Columbia Hydro Electric with Gilda Radner playing his mother. He was a very popular person in his school. During high school, to make girls laugh, he would go into the Wayne’s World character that later came to be known as Wayne Campbell. The day he finished his high school finals he joined Second City. Later, he left Second City to tour England with comedian Neil Mullarkey.

One of Myers' first acting jobs was in a TV commercial when he was ten years old.^[2] Gilda Radner played his mother. A few months later, according to Myers, his brother was teasing him about his "girlfriend (Radner) being on some stupid show on Saturday." Myers swore that one day, he too would be on that show.

Myers graduated from high school in 1982 and was immediately accepted into the Second City Canadian Touring Company, after which he moved to the UK where in 1985 he was one of the founding members of The Comedy Store Players, an improvisational group based at The Comedy Store in London. The next year, he starred in the British children's TV program Wide Awake Club, parodying the show's normal exuberance with his own "Sound Asleep Club", in partnership with Neil Mullarkey. He returned to Toronto and Second City in 1986 as a cast member in the Second City's Toronto main stage show. In 1988 he moved from Second City in Toronto to Chicago. In Chicago, he trained and performed at the Improv Olympic. He made numerous appearances, including as Wayne Campbell, on Toronto's Citytv in the early 1980s, on the alternative video show "City Limits" hosted by Christopher Ward. Myers also appeared as his Wayne Campbell character in the music video for Ward's Canadian hit "Boys and Girls". Later, Ward would appear as one of Austin Powers' band members in Ming Tea in Myers' popular movie series. The Wayne Campbell character was featured extensively in the 1986 summer series It's Only Rock & Roll produced by Toronto's Insight Production Company for CBC Television. Wayne appeared both in studio and in a series of location sketches directed and edited by Allan Novak. Myers wrote another sketch, Kurt and Dieter co-starring with Second City's Dana Andersen and also directed by Novak, which would later turn into the popular Sprockets sketch on Saturday Night Live. Myers has played for Hollywood United F.C., a celebrity studded U.S. soccer team.

He was a member of the cast of NBC's Saturday Night Live television program from 1989 to 1995, where he performed characters such as Simon, Dieter, Linda Richman, and Wayne Campbell from Wayne's World.

In 1992, Myers and comedian Dana Carvey adapted Wayne's World into a full-length motion picture based on the SNL sketch. The movie turned out to be one of Myers' greatest successes and one of the few Saturday Night Live-based films to be considered worthwhile by both audiences and film critics. It was among the most successful movies of the year and the following year a sequel was released - Wayne's World 2. That year Myers also starred in So I Married an Axe Murderer which garnered a cult following.

In 1997, Myers introduced Austin Powers in the film Austin Powers: International Man of Mystery later coming out with his sequel in 1999 Austin Powers: The Spy Who Shagged Me then finally topping it off with Austin Powers in Goldmember in 2002. Myers played both the title role and the villain, as well as other characters in all three Austin Powers films. In 1998, he played one of his rare non-comedic roles in the film 54: Steve Rubell, proprietor of New York City's famous Studio 54, a 1970s discotheque. The film was moderately successful, and Myers' performance was widely praised. Myers later parodied the club as "Studio 69" in Goldmember.

In June 2000, Myers was sued by Universal Pictures for $3.8 million for backing out of a contract to play Dieter, the SNL character, in a feature film. Myers said he refused to honor the $20 million contract because he didn't want to cheat moviegoers with an unacceptable script - one that he himself had written. Myers countersued, and a settlement was reached after several months where Myers agreed to make another film with Universal. That film would be The Cat in the Hat, released in November 2003 and starring Myers as the title character. In 2001, Myers played the title character in the DreamWorks animated film Shrek (2001). He reprised this role in Shrek 3-D in 2003, Shrek 2 (2004), Shrek The Third, and the Christmas special Shrek The Halls, both in 2007.

Myers is a member of the band Ming Tea along with Bangles guitarist and vocalist Susanna Hoffs and musician Matthew Sweet. They performed the songs BBC and Daddy Wasn't There for the Austin Powers movies.

In a 2005 poll to find The Comedian's Comedian, he was voted among the top 50 comedy acts ever by fellow comedians and comedy insiders. As of 2005, Myers was signed on to play the lead role in the upcoming biopic of The Who drummer Keith Moon.^[6] The film would be produced by Roger Daltrey and Nigel Sinclair.

During a CBS interview in 2007, Myers noted that he normally takes three years between films. He spends one year "living his life" and then writes multiple screenplays, develops characters, practices them in front of live audiences, and then selects one of the screenplays to film. Myers noted that this was the Marx Brothers' procedure for developing their film material.

Myers received the MTV Generation award in June 2007, making him the 2nd Canadian to win the award (Jim Carrey was the first in 2006), for bringing his unique style of comedy to small and big screens alike.

In June 2008, Myers's film The Love Guru met with negative reviews, prompting cable news network MSNBC to brand Myers "The Antifunny" in its June 24, 2008 online news edition.

In August 2008, it was announced that Myers had been cast as Gen. Ed Fenech in Quentin Tarantino's World War II revenge film Inglourious Basterds (which was a serious role in contrast to Myers' comic roles).^[7] The film was met with mostly positive reviews and represents something of a revival in Myers' career