The couple's nuptials kicked off on Saturday (29Jun13), with Lavigne and her Nickelback rocker beau heading to Cannes with around 100 guests.
They tied the knot at the Chateau La Napoule in Mandelieu on Monday (01Jul13), the official day of their native Canada, and Lavigne has explained why they decided to jet to Europe for the luxurious affair.
She tells Britain's Hello! magazine, "I wanted to make sure it's a crazy vacation and an experience of a lifetime for our guests. I wanted it to be over the top. I'm obsessed with castles and I love French decor and goth... I found this castle in France and we visited it and it was perfect."
Lavigne opted for a black tulle Monique Lhuillier gown for the nuptials, which marks her second trip down the aisle. She was previously married to Sum 41 star Deryck Whibley.