Christina Aguilera, Leonardo DiCaprio, Blake Lively and Scarlett Johansson were among the A-list stars who helped the Hurt Locker actor ring in his 40th birthday at his Hollywood Hills home on Saturday – a bash that's being called special even by Hollywood standards.
"It was one of the better Hollywood parties in a long time," one source tells PEOPLE. "Jeremy pretty much had a who's who of the industry come out to celebrate his birthday."
Lively and DiCaprio spent much of the evening laughing and chatting together, while Kevin Connolly and Johansson hung out together for the majority of the night. Other guests included Colin Farrell, Charlize Theron and Leslie Bibb.
Says the source: "All of Jeremy's family flew out to celebrate not just his 40th birthday but the remodeling of his new home in the Hollywood Hills."
Reporting by Dahvi Shira