Phair was signed through 2026 via the league’s under-18 entry mechanism, the Los Angeles-based team announced Thursday. She is Angel City’s youngest-ever signing.

“Her maturity and experience on the world stage in this past Women’s World Cup will help her have a smooth transition to the professional ranks. We’re excited to add depth to our front line and allow Casey an opportunity to grow and develop at Angel City,” team general manager Angela Hucles Mangano said in a statement.

Phair, the daughter of an American father and South Korean mother, was born in South Korea but grew up in the United States.

She appeared in the World Cup at 16 years and 26 days, entering South Korea’s opening match against Colombia as a substitute.

The youngest player previously was the late Ifeanyi Chiejine, who was 16 years and 34 days old when she played for Nigeria in the 1999 World Cup.

Phair was also the first multiethnic player, female or male, to play for a South Korean senior national team.

Phair trialed with Gotham FC and the Kansas City Current, in addition to Angel City, after returning from the World Cup.

“It feels like a dream come true. The first time I came to Los Angeles was last September. I trained with Angel City and fell in love with the culture and L.A.,” Phair said. “All of the players were super welcoming and I really enjoyed everything about the city.”