Flavin filed a request "for divorce of marriage as well as another relief" from the Rocky actor, 76, on the 5th of July in a courtroom located in Palm Beach County, Florida.
Stallone and Flavin 54, got became married in 1997, even though their relationship started in 1988 in a restaurant in Beverly Hills, California.
They have three daughters together: Scarlet, 20, Sistine 24 and Sophia and Sophia, both 25.
Stallone is also a father to his son Seargeoh of his earlier marriage to Sasha Czack.
The oldest son of his Sage who he has the same name with Starlin Wright, passed away in the year 2012.
In a statement made to PEOPLE, Stallone said, "I am a huge fan of my family.
We're working with them privately and amicably dealing with the personal concerns."