Posting snaps of their special day on Instagram, Harbour wrote: “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.
“Refreshments were served at a small reception following.”
The pair appeared to celebrate their marriage with a delivery from the US fast food chain In-N-Out Burger.
Allen, who wore a white bardot-style mini dress by Dior also shared a taste of their special day.
In one image, the British singer is seen eating a burger in her wedding dress, while another shows the elated couple just moments after tying the knot.
Allen was previously married to builder Sam Cooper, with whom she shares her two daughters.
In July, she marked a year of sobriety, saying she was “grateful” for her “health and happiness”.
Harbour, who plays Jim Hopper in the hit Netflix sci-fi series, was previously in a relationship with Fantastic Beasts And Where to Find them actress Alison Sudol.