Barenaked Ladies (BNL) is a Canadian rock band formed in 1988 in Scarborough. The band developed a following in Canada in the early 1990s with their cassette Barenaked Ladies (1991) and their debut album Gordon (1992). The band's popularity eventually spread to the United States following the release of versions of "Brian Wilson" and "The Old Apartment" from their 1996 live album, Rock Spectacle. In 1998, Barenaked Ladies released their fourth studio album, Stunt, which contains their highest-charting hit, "One Week", along with "It's All Been Done" and "Call and Answer". Their fifth album, Maroon (and lead single "Pinch Me"), also charted well. The band is also known for creating and performing the theme song of the American sitcom The Big Bang Theory. Barenaked Ladies has continued to regularly tour and record new music, having released 14 primary studio albums of original material and three themed studio albums.

Initially a duo of singer-guitarists Ed Robertson and Steven Page, the band grew to a quintet by 1990, adding brothers Jim and Andy Creeggan on bass and keyboards/congas, respectively, and drummer Tyler Stewart. Andy Creeggan left the band in 1995, and was replaced by multi-instrumentalist Kevin Hearn. Page left in 2009, reducing the group to a quartet.

The band's style has evolved, and its music (originally acoustic) grew to encompass a mixture of pop, rock and folk. Their live performances feature comedic banter and freestyle rapping between songs. They have received a number of Juno Awards, and have been nominated for two Grammy Awards. The group has sold over 15 million albums and singles, and was inducted into the Canadian Music Hall of Fame in March 2018.

Barenaked Ladies began as a duo of Ed Robertson and Steven Page. Both attended Churchill Heights Public School and met after a Peter Gabriel concert; they were counsellors at Interprovincial Music Camp in McKellar, Ontario. Page was impressed by Robertson's harmonizing when they began playing songs together. While attending a Bob Dylan concert at Exhibition Stadium, they decided on the name "Barenaked Ladies."

They first performed a largely-improvised set during a battle of the bands at Nathan Phillips Square for the Second Harvest food bank on 1 October 1988. The duo opened for the Razorbacks and others, developing their improvised set to include comedy, songs, and audience interactions.

Page and Robertson continued performing, and began writing songs together. Their first tape, Buck Naked (1989), was made with a four-track recorder in basements and bedrooms. They became followers of the comedy group Corky and the Juice Pigs, whom they credited with exposing them to a comedic stage presence. Page and Robertson presented the group with their tape, and were invited to open for the Juice Pigs on their national tour. Page and Robertson invited two friends from music camp, brothers Andy Creeggan (percussion) and Jim Creeggan (bass), to play with them at a 1989 Toronto Christmas show. With the Creeggan brothers, Barenaked Lunch (also known as The Pink Tape) was released in 1990.

Andy Creeggan left for a student-exchange trip to South America six months later, leaving the band without a percussionist. They met drummer Tyler Stewart in Waterloo, Ontario in the summer of 1990, and he joined the band. The band received attention during Andy Creeggan's absence, receiving the 1990 YTV Achievement Award for Best Band/Musical Group and squeezing into a Speaker's Corner video booth to perform "Be My Yoko Ono". Andy Creeggan returned in early 1991, playing keyboards, congas and other percussion instruments, and the band soon began their first Canadian tour.

The band's first commercial release was the 1991 tape Barenaked Ladies, more commonly known as The Yellow Tape. A demo tape created for South by Southwest, it was the first recording with all five members and was turned down by every Canadian record label. The band sold copies off the stage; people began asking for the tape at local stores, and it was released commercially. Sales increased due to word of mouth and the band's live shows. Page's father, Victor, founded the independent label Page Publications to manufacture and distribute the cassette.