The singer has teamed up with German-Russian record producer Zedd for the track and they've been Stateside shooting the video.
The pair have been sharing videos from the set to Snapchat and Instagram with Liam giving details.
"We've wrapped for the day and finished all the artwork so please enjoy," the One Direction star says in Zedd's Snapchat video.
The EDM producer spoke about the mystery song on Beats 1 radio, explaining that it would be the most urban-sounding track he's released so far.
"It's the definition a summer song," Zedd said.
"I think it’s a good balance between where he is going with his solo project and where I’m going with my own music… it’s insanely catchy and you’re gonna hate it after a while because it’s so catchy!"
Liam's debut solo single was released just a few weeks ago and it peaked at number three on the Official UK Singles Charts.
The song is called Strip That Down and was written by Ed Sheeran with Migos rapper Quavo featuring on it too.
However, the song also uses interpolations and samples from a serious amount other artists including Orville Burrell (Shaggy), Rikrok, Shaun Pizzonia, Brian Thompson, Sylvester Allen, Harold Ray Brown, Morris Dickerson, Lonnie Jordan, Charles William Miller, Lee Oskar, and Howard E. Scott.
Strip That Down's pre-chorus verse is an interpolation (when the melody from one song is used in the other with the lyrics changed) Shaggy and Rikrok's It Wasn't Me.