The singer, 38, posted a picture from their lowkey Las Vegas wedding celebrations on her social media account, showing a candid moment between the pair, with the couple gazing at one another and Allen laughing.
“Three years with this guy, second best decision I ever made,” she joked in her caption. “First was that dress.”
The dress in question was a short off-the-shoulder design by Dior, which set the tone for the pair’s non-traditional wedding day.
Allen and Harbour, 48, tied the knot at the Graceland Wedding Chapel in Las Vegas in September 2020. The ceremony was officiated by an Elvis Presley impersonator, and the newlyweds ate In-N-Out burgers with the musician’s two daughters, Ethel and Marnie, afterwards.
“In a wedding officiated by the king himself, the people’s princess wed her devoted, low born, but kind credit card holder in a beautiful ceremony lit by the ashen skies courtesy of a burning state miles away in the midst of a global pandemic,” Harbour wrote in an Instagram post confirmed the happy news at the time.
“Refreshments were served at a small reception following.”
The couple met on the celebrity dating app Raya and are thought to have started seeing each other in September 2019.
Allen later admitted on The Jonathan Ross Show that she “didn’t know who [Harbour] was” when she was swiping through the app, and revealed that Harbour had used a photo of himself in character as Stranger Things’ police chief on his profile.
“I thought he was just like a sexy policeman from a reality TV show,” she told Ross on his chat show. “He was wearing a policeman’s uniform.”
Allen was previously married to Sam Cooper, who is the father of her two daughters. The former couple separated in 2016 and then finalised their divorce in 2018.