Rumoured guests included music diva Christina Aguilera, who is heavily pregnant, and one of Sia's besties Demi Moore.
A source close to the couple also revealed that Britney Spears sent a very special message to them for their big day, and a wedding gift worth over $20,000!
Sia has turned her life around since 2010 when she realised she was "increasingly dependent on alcohol and drugs" and almost took her own life.
The star even went as far as to write a suicide note as she considered taking a lethal concoction of narcotics.
She was planning to check into a cheap hotel, and left instructions for her dog walker and the hotel manager in the note, writing: "I've killed myself and I don't want you to have to suffer seeing my dead body."
What if she wasn't even there? Maybe she only sent that party city wig from the album cover while she was sitting at home waiting for her man to come back from the ceremony.
Leave her alone on her wedding day lmao 