A fuel supply system includes a fuel supply channel and a joint unit. The joint unit includes first and second joint members and a sealing member. The first and second joint members are arranged to be connectable to and separable from each other. The sealing member is arranged to seal a gap between the first and second joint members in a state in which the first and second joint members are connected. The first joint member includes a first flow channel, a first valve, and a first fitting portion. The second joint member includes a second flow channel, a second valve, and a second fitting portion. The first valve has a first pressing end and a first valve body. The second valve has a second pressing end and a second valve body. The first and second fitting portions are arranged to fit each other.