Hefner, 86, married fiancée Crystal Harris, 26, in front of family and a few close friends at the Playboy Mansion in Los Angeles on Monday, the magazine publisher confirmed on Twitter.
"Crystal & I married on New Year's Eve in the Mansion with Keith as my Best Man. Love that girl!" he Tweeted early New Year's Day.
The bride wore a floor length strapless gown in soft pink and the groom wore a traditional black tuxedo, Playboy Enterprises said in a statement.
After the ceremony came a private reception with a champagne toast and the bride and groom cut the wedding cake.
The newlyweds then attended the Mansion's annual New Year’s Eve celebration and enjoyed a performance by jazz and blues singer Brenna Whitaker.
Hefner later shared another snapshot of the newlywed couple, with him sporting his iconic captain's hat and Harris in a pale pink wedding dress.
"Happy New Year from Mr. and Mrs. Hugh Hefner!" he wrote.
Guests included Joe Don Rooney of Rascal Flatts, 2005 Playmate of the Year Tiffany Fallon, baseball player Evan Longoria, Gene Simmons and wife Shannon Tweed and Jon Lovitz.
Ever the social media friendly couple, on the morning of their New Year's Eve wedding day, Harris shared her excitement via Twiter. "Today is the day I become Mrs. Hugh Hefner. Feeling very happy, lucky, and blessed," she Tweeted.
The wedding follows a failed engagement in 2011, when Harris called it off just days before the scheduled ceremony.
The couple revealed their reconciliation in June, when Harris Tweeted "Yes I am his #1 girl again. Yes we are happy. Hope that clears up any confusion! Xo."
Amid speculation regarding their relationship status, Hefner confirmed the couple's plans to walk down the aisle once again.
"I've given Crystal Harris a ring. I love the girl," he Tweeted.
Harris later showed off the diamond sparkler on the social media service, calling it "my beautiful ring."
This is the third marriage for Hefner and the first for Harris.
Crystal & I married on New Year's Eve in the Mansion with Keith as my Best Man. Love that girl! twitter.com/hughhefner/sta…— Hugh Hefner (@hughhefner) January 1, 2013