Sir is a higher prefix title in English, so it would technically be Sir. May
When being fully formal, you use the highest title before your name.
I can imagine, however, if it was something to do with your career, e.g. if you were a doctor/professor as well as a sir, you'd put the career prospect title first.
Thorebane t1_j2beri6 wrote
Reply to comment by atreides78723 in Brian May gets a knighthood in New Year Honours list by StephenHunterUK
Sir is a higher prefix title in English, so it would technically be Sir. May
When being fully formal, you use the highest title before your name.
I can imagine, however, if it was something to do with your career, e.g. if you were a doctor/professor as well as a sir, you'd put the career prospect title first.