The pair dropped the track, which is produced by Max Martin, Shellback and FRED, on Friday morning (10.05.19) alongside an accompanying lyric video.
Ed, 28, wrote on Instagram: ''Me and @justinbieber have got a new song out. It's called ''I Don't Care'' hope you like it x (sic)''
Justin, 25, tweeted: ''It's out. I don't care (sic)''
The 'Company' hitmaker seemed to enjoy doing a countdown ahead of the song's release.
He tweeted: ''Been a long time since I've done a countdown to new music:) 20 minutes to go. #IDC (sic)''
Ed celebrated the release with some beers in Cambodia, where he is currently holidaying with his wife Cherry Seaborn, and he asked fans to play the song ''loud''.
On Thursday (09.05.19), he wrote: ''Hope everyone enjoys the music coming out tomorrow. I'm super happy and proud of it. I'm currently in Cambodia in the jungle, but I've got a few bottles of beer for me and Cherry (and @securitykev) to celebrate the release tomorrow. Please play the song loud, dance, sing, smile to it. And tell your mum. Love you all x (sic)''
'I Don't Care' appears to be about not fitting in but not worrying about things when you are with a significant other.
Some of Ed's lyrics on the tune include: ''Cause I don't care when I'm with my baby, yeah, all the bad things disappear.
''And you're making me feel like I maybe I am somebody.''
And Justin sings: ''I can deal with the bad nights when I'm with my baby, yeah. Cause I don't care.''
'I Don't Care' is Justin's first single as a lead artist since 2017's 'Friends'.
That song came after he released four singles from his fourth studio album 'Purpose', including 'Sorry' and 'Lose Yourself', which was written by Ed.
Ed's last single was 'Happier', which he dropped in April last year, the fifth tune from his third studio album 'Divide'.
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