A high-pressure gas tank connection structure including: a tank main body; a tank side connector; a connection side connector; and a valve body, the valve body being provided further toward a deep side along the axial direction of the tank main body than the tank side connector, the valve body being urged toward the connection side connector, and, in a case in which the valve body is pushed by a distal end of the convex portion in a state in which the convex portion is joined with the concave portion, the valve body being opened from a closed state, and communicating the interior of the tank main body with the exterior to the tank main body.