The Mrs. Doubtfire star, 60, married graphic designer Susan Schneider in an intimate ceremony at the Meadowood Resort in St. Helena, California on Sunday (23Oct11).
Guests reportedly included Steven Spielberg, George Lucas and Billy Crystal.
Williams met Schneider shortly before he underwent heart surgery in March, 2009, and she helped nurse him back to full health.
He was previously married to Valarie Velardi, the mother of his eldest son Zak, and he split from his second wife, Marsha, in 2008 after 19 years of marriage.
The actor has two children with Marsha – 22-year-old daughter Zelda and 19-year-old son Cody.