A canister structure for a saddle riding vehicle, including a canister connected with a fuel tank using a connection line, the canister adsorbing fuel vapor generated in the fuel tank, and a purge valve disposed in a path through which the fuel vapor is returned from the canister to an air intake system of an engine, includes an annular canister rubber that fits over an outer cylinder of the canister; a canister stay disposed on a vehicle body side; and an engagement portion disposed on the purge valve. In the canister structure, the canister rubber has, formed on an outer periphery thereof, an anterior-side mounting portion and a posterior-side mounting portion each having an insertion hole in which the canister stay is inserted and a purge valve mounting portion having an engagement portion insertion hole in which the engagement portion of the purge valve is inserted.