Sulfometuron methyl is an organic compound used as an herbicide. It is classed as a sulfonylurea. It functions via the inhibition of the enzyme acetolactate synthase, which catalyzes the first step in biosynthesis of the branched-chain amino acids valine, leucine, and isoleucine.

Sulfometuron methyl's HRAC classification is Group B (global, Aus), Group 2 (numeric), as it inhibits acetohydroxyacid synthase.