Lily Allen and David Harbour have made their relationship public by stepping out at an event together.

The British singer-songwriter and the American Stranger Things star appeared at the Skin Cancer Foundation Champions For Change Gala in New York on Thursday evening.

Allen, who is believed to have been in a relationship with Harbour since the summer, appeared to confirm their romance on Instagram earlier this week, and they were also pictured locking lips while out for a walk in New York.

Skin Cancer Foundation 'Champions For Change Gala', New York, USA - 17 Oct 2019
David Harbour and Lily Allen at a charity event in New York (Startraks Photo/Shutterstock)

Smile singer Lily, 34, posted a picture of Harbour, 44, from his stint hosting entertainment programme Saturday Night Live on her Instagram story with the word “mine” written over it.

The pair were first spotted together on what appeared to be a date in London in late August at a boxing match at the O2 Arena.

Their union comes after Allen announced her split from her boyfriend of three years, rapper Meridian Dan.

She was previously married to builder Sam Cooper, with whom she has two daughters.

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.

The pair were pictured together at the Vanity Fair Oscars party in February, but they are believed to have split a few months later.