Whoopi Goldberg, Denise Richards and Kevin Connolly are among the stars who have reached out to Sylvester Stallone after his son was found dead on Friday.
Sage Stallone's body was discovered in his Studio City, California apartment. He was 36.
The Rocky star shared his grief with fans via a statement from his publicist late on Friday, and his celebrity friends have since flocked to Twitter to offer up their support.
"My heart goes out to TheSlyStallone & your family...." Richards tweeted.
Lisa Marie Presley wrote "My heart goes out to Sylvester Stallone and his family for their incredible tragedy and loss."
Entourage star Connolly took to his account to reminisce about his late friend, recalling, "Sage Stallone... Great memories... I'll always remember you and I running Philly in 1990. Rest in peace brother."
Goldberg tweeted "A really great guy has lost his son today Sending much love to Sylvester Stallone and the family.
Hug ur kids, life can change so quickly, tell them how much they mean to u. They are never to (sic) old to hear it. 2 b (to be) clearer tell ur mothers and fathers sisters and brothers what they mean to u. NO ONE is ever too old to hear that they matter."
Police have said that there is "no suspicion of foul play or criminal activity" in Sage's death.