The ceremony took place Saturday at Geoffrey's Malibu, including a wedding party of Chaillot's four sisters and Louganis' Olympic diving coach Ron O'Brien, People magazine reported.
"It was amazing because I have so many people from all facets of my life here tonight and they are all here and celebrating it is all wonderful," Louganis, 53, told People after the ceremony. "I already feel different. The ceremony was so reflective and representative of who we are."
The grooms wore European-cut white suits and enjoyed music performed by friends, including "The Voice" contestant Dominic Scott Kay.
In lieu of wedding gifts, the couple asked guests to donate to the Human Rights Campaign and Mending Kids International.
"We are both in our mid 50s and don't need another blender so we really wanted to give back," Chaillot, 52, said.