Buttafuoco, 50, walked out of Los Angeles County Jail just before 9 a.m. Saturday, according to the Sheriff's Department Web site.
The release was first reported by the syndicated television program "The Insider."
Buttafuoco pleaded no contest in July to illegally possessing ammunition. The case stemmed from a search of his Chatsworth home in 2005 by the Los Angeles County Probation Department.
At the time, Buttafuoco was on probation for a felony insurance fraud conviction.
Prosecutors said Buttafuoco, who co-owned a San Fernando Valley auto body shop, told undercover investigators how to file false claims and cheat insurance companies.
Buttafuoco was running an auto body shop on New York's Long Island in 1992 when his 17-year-old lover, Amy Fisher, shot his wife in the face as she answered the door at the couple's home.
Fisher, nicknamed the "Long Island Lolita," served seven years in prison. Buttafuoco pleaded guilty to one count of statutory rape and served four months in jail.
His wife, Mary Jo, recovered. The couple remained together after the Fisher affair but divorced after moving to California.