The NBA named Booker as Lillard's replacement in a news release Thursday, one day after Lillard sustained a right groin strain.
Booker, 23, will make his first All-Star appearance in his fifth season in the league. The Kentucky product is the NBA's 10th-leading scorer this season, averaging 26.4 points per game.
Booker will be a member of Team LeBron in the All-Star matchup. LeBron James, who is one of the captains alongside Milwaukee Bucks star Giannis Antetokounmpo, welcomed Booker to his team with a post on social media Thursday.
Booker becomes the Suns' first All-Star since Steve Nash in 2011-12. Although it is his first appearance in the game, Booker has been part of All-Star festivities in each of his five seasons in the league.
The sharpshooter has competed in the 3-point contest three times and won the event in 2018. He also participated in the 2016 and 2017 editions of the Rising Stars Game.
The 69th NBA All-Star Game will take place Feb. 16 at 8 p.m. EST in Chicago.