Ed Sheeran does not use autotune in his live performances, but like most singers in the pop industry, he uses software like Melodyne to correct slightly off-pitched parts in his recordings, the corrections are very subtle and hard to notice.
Ed Sheeran is a pretty amazing singer who does not need autotune to sing successfully. In general, he does not much autotune or heavy effects to make his voice unnatural. Instead, he relies on his natural voice for singing and embraces the slight off-pitch parts as mistakes are part of being human, and perfection belongs to robots.
However, in the recording process of his songs, he gets some help like most singers today. His production team uses programs like Melodyne to correct some parts of his vocal lines in the studio. As Ed Sheeran is a pretty successful singer, there are not many things to correct, but the subtle corrections can be heard in some parts of his songs.
You can notice these corrections if you carefully listen to the studio and live version of his song “Castle On The Hill.” His live performance is pretty fantastic, even though he plays the guitar at the same time, but in the studio recording, the perfection is unmistakable.
One of the reasons Ed Sheeran is so loved by many people is the truthfulness and talent behind his voice. As an industry standard, he uses pitch correction in the studio, but his voice is entirely natural in each of his live performances.