The now-single Mayer, 36, who split with Katy Perry in February, makes the intimate love song – which urges, "Baby love me, lights out" – his own soothing romantic journey.
Even better news for fans: Mayer – who first performed the song live onstage in Adelaide, Australia – loved the song so much, he's recorded it and will be releasing the track on iTunes on Tuesday.
The pop singer, who recently wrapped up the Asia leg of his tour and will be hitting Europe next month, acknowledged Queen Bey's formidable vocal talents in a Tweet he posted in April about the song.
"The best thing about Beyoncé? The break in her voice on the first 'baby, love me lights out' in XO. Real and raw."
What do you think? Does Mayer do the song justice? Sound off in the comments below.