It is believed the duchess and her husband, Prince William, were among the guests at the wedding, along with James' sister Pippa Middleton and her spouse James Matthews.
The couple had previously cancelled their wedding twice due to the coronavirus pandemic.
In September 2020, James revealed the couple had marked a year since their engagement on vacation in Italy and admitted it had been a hectic 12 months.
He wrote on Instagram: "It's a year since I asked Alizee to marry me … what a year it's been!
"Two homes, lockdown, two attempts at a wedding, a litter of [puppy emoji], launching of new company, a beard shave and much more but the best part is that I get to share it with you @alizeethevenet and I can't wait to take on whatever the future holds for us.
"We managed to escape to Italy for a quick dip in the the sea, lots of [pasta and wine emojis] and now ready to face the world again."
The Boomf founder previously credited his dog for him meeting the French financial analyst.
He previously explained: "The two of us (Ella and me) were at the South Kensington Club in Chelsea. Ella was lying at my feet under the table; realising she might want some water, I trusted her to take herself over to the water bowl across the terrace.
"However, she made a beeline for Alizée. Rather embarrassed, I went over to apologise and bring Ella back.
"But Alizée thought I was the waiter and ordered her drink while continuing to stroke Ella, who at this point was on her back lapping up the attention.
"Little did I know, but I had just met my future wife, all thanks to Ella. If I hadn't trusted Ella, I wouldn't have brought her to the South Kensington Club and she wouldn't have been able to say hi to the woman who became my fiancée."
