Benson Boone has a special guest for his set at Coachella ... and it's Queen guitarist Brian May!!!

Our sources tell us Brian will join Benson onstage at some point during Benson's Friday night set at the famous music festival.

Benson and Brian have boots on the ground in the desert ... we obtained a photo of them getting off a private jet at the Palm Springs private airport earlier Friday morning ahead of their collab performance.

Brian shared a photo from inside the plane -- showing him seated across from Benson in a private jet -- and while Brian claimed they just happened to bump into each other, our sources say the flight was definitely coordinated, and they had their managers traveling with them too.

Benson's drawn comparisons to Freddie Mercury, so a collab with Queen's guitarist and backup vocalist makes a lot of sense ... though it's unclear what songs Benson and Brian will perform together.

Benson is scheduled to take the main stage at 7:05 PM PT for an hourlong set ... and this will be Brian's first time at the famed music festival.