A coolant passage in a cylinder head of a multi-cylinder internal combustion engine is divided into an intake-side passage below intake ports and extending in a cylinder arranging direction, and an exhaust-side passage including plural exhaust-side lateral passages corresponding to respective cylinders and an exhaust-side longitudinal passage. The exhaust-side lateral passages (1) are mutually separated by partition walls at a position corresponding to the section between a corresponding adjacent pair of the cylinders, (2) have an inlet for coolant in the vicinity of exhaust ports of a corresponding one of the cylinders, and (3) extend from the inlet toward the intake port via the vicinity of a top of a combustion chamber formed in the corresponding cylinder. The exhaust-side longitudinal passage extends along the cylinder arranging direction. Downstream ends of the exhaust-side lateral passages connect to the exhaust-side longitudinal passage.