The wedding was held at the Meadowood resort in St. Helena in the wine region of Napa Valley.
Williams, 60, met Susan just before he underwent heart surgery in 2009 and credits her with nursing him back to health at his Los Angeles home.
Susan told the San Francisco Chronicle in the days leading up to her nuptials that she was “so excited and so thrilled” to be getting married.
Robin divorced from his second wife Marsha last year after 22 years of marriage and he has two children; Zelda, 22, and Cody, 19, with her.
He also had a son Zachary, 28, from his first wife Valerie who he split from in 1988 after 10 years together.