Gest, 50, alleges in court papers that Minnelli, 57, flew into drunken rages on several occasions on both sides of the Atlantic, insulting and striking him.
Liz Rosenberg, a spokeswoman for the singer, said Minnelli had not seen the lawsuit and could not comment. Minnelli's lawyer, Allen Arrow, did not immediately return a call seeking comment.
Minnelli and Gest separated in July, just 16 months after they wed at a celebrity-studded ceremony that featured best man Michael Jackson (search) carrying the bride's train. Elizabeth Taylor (search) served as maid of honor.
In papers filed in Manhattan Supreme Court, Gest alleges that Minnelli began battering him before the wedding.
Gest's lawyer, Raoul Felder, said his client suffered neurological damage and headaches from the alleged attacks, and is staying at a rehabilitation clinic in Honolulu.
In one incident last June in London, court papers allege Minnelli consumed a bottle of vodka before she threw a lamp at Gest in their hotel suite.
She later "began beating (Gest) about the head and face with her fists," the lawsuit said. When Gest asked a security guard to intervene, court papers say Minnelli punched him in the stomach.
When the couple married in March 2002, attendees said Minnelli danced in happiness at the altar. Hundreds of fans lined Fifth Avenue to watch guests including actors Michael Douglas, Anthony Hopkins and David Hasselhoff, rocker Elton John and TV news personality Barbara Walters arrive in limousines.
The wedding marked a personal comeback for Minnelli, the daughter of Judy Garland (search) and director Vincente Minnelli (search). She has won an Academy Award, an Emmy, two Golden Globes and three Tony Awards but also battled substance abuse, weight gain, and a near-fatal bout with encephalitis (search).
Gest, an event and concert promoter, produced Jackson's 30th Anniversary tribute concert.