Mr. Children (Japanese: ミスターチルドレン, Hepburn: Misutā Chirudoren), commonly referred to by their contracted nickname "Misu-Chiru" (ミスチル), are a Japanese pop rock band formed in 1989. Consisting of Kazutoshi Sakurai, Kenichi Tahara, Keisuke Nakagawa, and Hideya Suzuki, they made their major label debut in 1992. They are one of the best selling artists in Japan and one of the most successful Japanese rock artists, having sold over 75 million records and creating the "Mis-chil Phenomenon" (ミスチル現象) in the mid-1990s in Japan. They held the record for the highest first week sales of a single in Japan for 15 years, with 1.2 million copies of their 10th single "Namonaki Uta" (名もなき詩), have 30 consecutive number 1 singles, replaced Glay as the all-male band (with 3 or more members) to have the most number 1 albums on the Oricon charts, and won the Japan Record Award in 1994 for "Innocent World" and in 2004 for "Sign". As of 2012, Mr. Children has published fifteen original studio albums and 34 physical singles, along with five compilations, a live album, and fifteen home video releases.

The band's music is mainly composed and written by lead singer Sakurai, with the exception of the Suzuki-penned songs "Asia" and "#2601" from the albums Atomic Heart and Discovery, and occasional collaborative song writing with producer Takeshi Kobayashi.[a]

In 2012 they celebrated their 20th debut anniversary by releasing dual best album titled Mr. Children 2001–2005 ＜micro＞ and Mr. Children 2005–2010 ＜macro＞. Both albums dominated the best-selling album category in the 2012 Oricon yearly chart, selling over 2.5 million copies. Mr.Children has become the third artists who achieved TOP 2 spots on the yearly album ranking, and this is the first time in 14 years for any artist to achieve this. Moreover, [(An Imitation) Blood Orange], an album of new material released in November 2012, debuted No.1 on the Oricon Chart—at the end of the year, all three albums released that year were in the Top 10 best selling albums of 2012.

In 2015, Mr. Children was named No.1 Concert Mobilization Power Ranking based on the overall number of people whom attended their performances during 2015 in Japan, mobilizing 1,119,000 fans (36 concerts).