The 42-year-old actress wore a Balenciaga wedding gown and a long veil as she exchanged vows with Pinault, 46, at Venice's opera house La Fenice.
The couple's 19-month-old daughter Valentina was a flower girl alongside Pinault's son Francois, 10, and daughter Mathilde, 8, from a previous marriage.
About 150 family and friends attended the ceremony, including Penelope Cruz, Edward Norton, Woody Harrelson, Olivier Martinez, Ashley Judd, Charlize Theron, Bono, Ziyi Zhang, Anna Wintour and former French President Jacques Chirac.
Guests wore black tie with black and gold masks as they arrived for the ceremony, which started at 7pm.
Wedding celebrations kicked off on Friday with a masquerade ball in Venice's Punta Della Dogana.
Salma recently vowed she would never splash out a fortune on a marriage ceremony. She said: "I think a wedding is about love, friends, family and fun. I think spending millions of dollars on a wedding is ridiculous and it has never been my dream. I would never do that."
Salma and Francois-Henri - who began dating in 2006 - called off their engagement last July, but eventually decided to get back together after taking two romantic trips to the French capital.