It was topped off by a flowing vintage-style veil which doubled as a train, and the singer carried a bouquet of dark red blooms.
Nick, meanwhile, looked dapper in a Dolce & Gabbana suit with a blue velvet jacket.
The jet-setting duo, who got engaged in the Maldives, welcomed family and friends from both their home countries: Australia and England, to LA, where they met in 2009.
Famous faces watching as the couple exchanged vows included X Factor mogul Simon Cowell.
Nick, 39, wed Holly – who is ten years younger – on Saturday at a sprawling stately mansion. Their big day was more a big weekend, however, with celebrations spread out over three days.
The couple held a rehearsal dinner in Malibu on Friday evening, and organised an informal ' recovery' barbecue on Sunday.
After the ceremony, Holly changed her Twitter handle to @Hollycandy.