"The X Factor" U.K. stars Little Mix, Cheryl Cole and Union J are among the artists scheduled to perform at the 2014 Capital FM Summertime Ball, which takes place on June 21 at Wembley Stadium in London.
Other artists performing at the event include Miley Cyrus, Ellie Goulding, Ed Sheeran, 5 Seconds of Summer, Jessie J, Enrique Iglesias, Rita Ora, Sam Smith, the Vamps, Clean Bandit and Duke Dumont.
Little Mix was the winner of "The X Factor" U.K. in 2011.
Cole was a judge on "The X Factor" U.K. from 2008 to 2010. In 2014, she returned to "The X Factor" U.K. judging panel.
Union J came in fourth place on "The X Factor" U.K. in 2012.
Little Mix has released two albums so far: "DNA" and "Salute." Both albums were Top 10 hits in several countries.
Cole (a former member of Girls Aloud) has not done a solo concert in the U.K. since 2012, when she toured for her third solo album, "A Million Lights." She is working on her fourth solo album, whose title and release date are to be announced.
Union J's self-titled first album was a Top 10 hit in the U.K. when it was released in 2013. There are no immediate plans for the album to be released in the U.S., although Union J's song "Carry You" was on the "Kick-Ass 2" soundtrack." Union J also briefly appeared in "Kick-Ass 2."