M-33 is a north–south state trunkline highway in the US state of Michigan that runs from Interstate 75 (I-75) at Alger in Arenac County north to M-27 near Cheboygan. In between, the trunkline runs through rural sections of the northeastern Lower Peninsula including state and national forest areas. M-33 connects to a handful of parks and crosses several of the rivers in that section of the state. It runs concurrently with three other state highways, sharing pavement to connect through several small communities of Northern Michigan.