An internal combustion engine includes a cylinder head including an intake port, an exhaust port, a water jacket, an intake valve, an exhaust valve, an intake valve seat, and an exhaust valve seat. The water jacket is positioned between the intake port and the exhaust port. The intake valve includes an intake valve head, and the exhaust valve includes an exhaust valve head. The intake valve contacts an intake valve seat surface of the intake valve seat. The exhaust valve head contacts an exhaust valve seat surface of the exhaust valve seat. The shortest distance between the water jacket and the intake valve seat surface is shorter than the shortest distance between the water jacket and the exhaust valve seat surface.