The ex-One Direction member has recently visited Italy and Germany, reportedly working on fresh music tracks.
It’s unclear whether his presence coincided with the election of Pope Leo by design or chance.
He seemed to prefer remaining unnoticed, donning sunglasses, a popped collar, and a blue hat.
Nonetheless, he was spotted and recorded by eagle-eyed fans.
Styles’ most recent album, 2022’s Harry’s House, was a critical and commercial success, winning accolades at the Grammys and MTV Video Music Awards.
White smoke billows from Sistine Chapel chimney as new pope elected
The crowds were thick in Rome and the Vatican, as the massed faithful and onlookers celebrated the election of the first US-born pope.
Leo spoke to the assembly in Spanish and Italian, arrayed in the papal regalia.
The conclave was the briefest in more than a century, with the cardinal electors only going into seclusion on May 7.
