Exo (Korean: 엑소; RR: Ekso; stylized in all caps) is a South Korean-Chinese boy band based in Seoul formed by SM Entertainment in 2011 and debuted in 2012. The group consists of nine members: Xiumin, Suho, Lay, Baekhyun, Chen, Chanyeol, D.O., Kai and Sehun. They are noted for releasing music and performing extensively in Korean, Mandarin and Japanese.

The group debuted with twelve members separated into Exo-K (Suho, Baekhyun, Chanyeol, D.O., Kai and Sehun) and Exo-M (Xiumin, Lay, Chen, Kris, Luhan and Tao). Members Kris, Luhan, and Tao departed the group individually amid legal battles with SM Entertainment in 2014 and 2015. Exo-K and Exo-M performed music in Korean and Mandarin, respectively, until the release of their third EP Overdose in 2014. Since then, Exo have exclusively performed as one group, although their music continues to feature multiple languages. Members Chen, Baekhyun, and Xiumin debuted in the sub-unit Exo-CBX in 2016, and members Sehun and Chanyeol began promoting as the sub-unit Exo-SC in 2019. Each member also maintains solo careers in music, film and television.

Exo's first studio album XOXO (2013), released alongside breakthrough single "Growl", was received positively by critics and sold over one million copies with its repackage, making Exo the first Korean act to do so in twelve years. The group's later works expanded on their early commercial success, with their subsequent Korean studio albums combined with their repackages each selling over one million copies. Exo's sixth studio album, Don't Mess Up My Tempo (2018), became their highest-charting album on the US Billboard 200, debuting at number 23. Their eighth studio album, Exist (2023), is their best selling album in South Korea, where it sold over 2 million copies.

Exo have won numerous awards, including five consecutive Album of the Year awards at the MAMA Awards and two consecutive Artist of the Year awards at the Melon Music Awards, and have performed over 100 concerts across four headlining tours and multiple joint tours. The group ranked as one of the top five most influential celebrities on the Forbes Korea Power Celebrity 40 list from 2014 to 2018. They have been labeled "Nation's Pick" by the Korea Tourism Organization and by some as the "Kings of K-pop". Outside of music, the group members have endorsed brands such as Nature Republic and Samsung and participate in philanthropic efforts such as Smile For U, an ongoing project by SM Entertainment and UNICEF that began in 2015.