A fuel supply apparatus comprises a filler neck body including a hollow fuel passage-forming structure configured to form a fuel passage and a fuel vapor port branched off from the fuel passage-forming structure; and a nozzle guide formed in a tubular shape to introduce a fueling nozzle. The nozzle guide includes a vapor flow path portion configured to introduce fuel vapor flowing into the fuel vapor port in a tank direction. The vapor flow path portion has a slow-down portion configured to slow down the fuel vapor introduced in the tank direction.