Hopefully not upstaging the bride in the process, the Black Eyed Peas singer wore a leather corset, feathered cape and gold mini-skirt as she joined husband Josh Duhamel.
The handsome couple were attending the Los Angeles nuptials of Black Eyed Peas producer Keith Harris and dancer Brandee Stephens.
While Duhamel, 38, kept it traditional in a black suit, his 35-year-old wife was obviously going for a more rock 'n' roll look.
As they arrived at the Park Plaza Hotel, the couple stopped to chat to Fergie's Black Eyed Peas bandmate Taboo and his wife of three years, Jaymie Gomez.
Taboo, real name Jaime Luis Gómez, wrote on his Twitter: 'Congrats on your wedding today. I will be representing with you brother .. Much love to Keith and Brandee.
'I need you all to wish my brother congratulations for his big day today he is getting married and he and his wife are BEP family.'
The groom himself also found time to write on his Twitter before the day kicked off: 'Well the the Best Day of my Life is Here! Keith Harris and Brandee Stephens will become 1 in the eyes of God Almighty! Love you all.'
Notably absent as the bash was Will.I.Am - who has spent the past week in Brazil - and bandmate Apl.De.Ap.
He was having his own celebrations at the Carnival in Rio De Janeiro, where he was partying with the likes of Jude Law, Gisele Bundchen and Pamela Anderson.
The bride and groom have been long associates of The Black Eyed Peas, with Harris winning a Grammy Award for producing their last album The E.N.D.
He's also written and produced some of hip-hop's biggest tracks, including Estelle's American Boy and Busta Rhymes' I Love My Chick.
Harris actually proposed to Stephens during a Black Eyed Peas concert in Las Vegas in December 2009, when she was dancing.
At one point, Fergie held the microphone up to Harris as he bent down on one knee to present Stephens with a ring
The wedding took place at the Park Plaza Hotel in downtown Los Angeles.