USA winger Timothy Weah signs for Juventus from Lille
"Timothy Weah has officially become a Juventus player. The American arrives on a permanent deal from Lille," the Italian club said in a statement.
The son of 1995 Ballon d'Or winner and current president of Liberia George Weah, the 23-year-old will replace Colombia winger Juan Cuadrado who is set to leave as a free agent.
Weah senior starred for Monaco, Paris Saint-Germain and then AC Milan, where he won league titles in 1996 and 1999 and was Africa's top scorer in Serie A until Victor Osimhen overtook him last season.
His son, who has played 29 times and scored four goals for the USA, is Juve's first new signing of the summer after a troubled season.
Juve finished seventh in Serie A after a 10-point deduction for illicit transfer activity which means they might not have European football next term despite earning a spot in the Europa Conference League.
The Turin giants could be banned from Europe for a season by UEFA for allegedly misleading European football's governing body when negotiating a "settlement agreement" following breaches of Financial Fair Play rules.
Juve are hoping to hire as their new sporting director Cristiano Giuntoli, the man who built a series of strong Napoli teams including last season's Scudetto winners while balancing the books.
Giuntoli has another year left on his contract with Napoli but is aiming to conduct the summer transfer window for Juve, who have posted losses for five straight years and whose most recent annual accounts were 254.3 million euros (£218.6 million) in the red.