The 36-year-old singer performed an acoustic rendition of the song to audience applause during his concert on Tuesday evening.
The star had expressed admiration for Beyoncé and "XO" on his Twitter only days before.
The best thing about Beyoncé? The break in her voice on the first "baby, love me lights out" in XO. Real and raw.— John Mayer (@JohnMayer) April 13, 2014
The Adelaide performance was just one stop in Mayer's ongoing Born and Raised World Tour. The tour promotes the singer's albums Born and Raised (2012) and Paradise Valley (2013), and kicked off in Milwaukee, Wisc. on July 6, 2013. Mayer's final stop is in Indre By, Denmark on June 17.