8-hydroxyfuranocoumarin 8-O-methyltransferase (, furanocoumarin 8-methyltransferase, furanocoumarin 8-O-methyl-transferase, xanthotoxol 8-O-methyltransferase, XMT, SAM:xanthotoxol O-methyltransferase, S-adenosyl-L-methionine:8-hydroxyfuranocoumarin 8-O-methyltransferase, xanthotoxol methyltransferase, xanthotoxol O-methyltransferase, S-adenosyl-L-methionine:xanthotoxol O-methyltransferase, S-adenosyl-L-methionine-xanthotoxol O-methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:8-hydroxyfurocoumarin 8-O-methyltransferase. This enzyme catalyses the following chemical reaction
8-hydroxyfuranocoumarin 8-O-methyltransferase converts xanthotoxol into xanthotoxin.