He’s sung with music superstars Adele, Stevie Wonder and Elton John but James Corden was joined by Hollywood acting royalty for his latest Carpool Karaoke.

The British funnyman hit the road with Gwen Stefani as the pair belted out her biggest hits, before they were joined by two surprise back seat passengers – George Clooney and Julia Roberts.

James, Gwen, George and Julia sang Hollaback Girl together before performing their own rendition of We Are The Champions by Queen.

James Corden and Gwen Stefani in Carpool Karaoke fun  (CBS/screengrab)
James Corden and Gwen Stefani in Carpool Karaoke fun (CBS/screengrab)

George and Julia, not known for their musical talent, gave a faultless performance as they hit every lyric of Gwen’s song.

And Gravity star George had his own explanation for the song’s words.

“Ain’t No Hollaback means if guys are on a construction site and they’re yelling at a girl, she’s not going to turn back, she’s not that kind of a girl,” George said.

But James failed to impress George when he revealed his favourite line from Julia’s movies.

After quoting “I’m just a girl standing in front of a boy, asking him to love her” from Notting Hill, George told James: “Now I’m not sure I want you to drive.”

George Clooney and Julia Roberts in Carpool Karaoke (CBS/screengrab)
George Clooney and Julia Roberts in Carpool Karaoke (CBS/screengrab)

And after arriving at work, James urged George and Julia to get an Uber home.