The "Smile" hitmaker shared a sweet post on Instagram giving fans a peek into their intimate Las Vegas ceremony which took place in September last year (20), including several throwback photos of her daughters who acted as flower girls.
While a video showed the 36-year-old and her spouse, 46, performing a dance and smashing their tasty dessert that read "Happy Anniversary" at a celebratory meal to mark the occasion.
Lily's daughters, Ethel and Marnie, who she shares with ex-husband Sam Cooper, are seen in the snaps dressed in cute matching pink ruffled dresses and holding pink and orange roses.
They were standing inside the famous Graceland Wedding Chapel in Las Vegas with Elvis impersonator Brendan Paul in the background, who carried out the ceremony.
"1 year down with this guy. Happy Anniversary baby @dkharbour. I prefer my life with you in it. You can stay," she captioned the post.
Lily wore a short white Dior blazer dress for her wedding, which she paired with black suede platforms heels and a veil, while another snap showed her sporting a leopard print Ganni coat.
The pair went public with their relationship in 2019 after they were spotted together at a West End production of "The Lehman Trilogy".
They were spotted kissing at Madison Square Garden in October and went on to make their red-carpet debut at the SAG Awards in January 2020.