An outboard motor comprising: a V-shaped 4-cycle engine including: a crankshaft extending in a vertical direction; a left bank extending in an obliquely rearward and leftward direction which includes a cylinder having a cylinder axis line extending in an obliquely rearward and leftward direction; and a right bank extends in an obliquely rearward and rightward direction which includes a cylinder having a cylinder axis line extending in an obliquely rearward and rightward direction; wherein the left bank and the right bank each include: a cylinder block including the cylinder provided therein; and a cylinder head secured to the cylinder block so as to cover the cylinder along the cylinder axis line and defining a combustion chamber together with the cylinder, characterized in that the cylinder head including an intake port arranged inward relative to the cylinder axis line in an outboard motor width direction and in communication with the combustion chamber and also including an exhaust port arranged outward relative to the cylinder axis line in the outboard motor width direction and in communication with the combustion chamber; and the outboard motor further comprises: a crankcase including the crankshaft accommodated therein; a left exhaust path arranged outward relative to the crankcase and the left bank in the outboard motor width direction and in communication with the exhaust port in the left bank; a right exhaust path arranged outward relative to the crankcase and the right bank in the outboard motor width direction and in communication with the exhaust port in the right bank; a left catalyst located inside the left exhaust path; and a right catalyst located inside the right exhaust path. a V-shaped 4-cycle engine including: a crankshaft extending in a vertical direction; a left bank extending in an obliquely rearward and leftward direction which includes a cylinder having a cylinder axis line extending in an obliquely rearward and leftward direction; and a right bank extends in an obliquely rearward and rightward direction which includes a cylinder having a cylinder axis line extending in an obliquely rearward and rightward direction; wherein a crankshaft extending in a vertical direction; a left bank extending in an obliquely rearward and leftward direction which includes a cylinder having a cylinder axis line extending in an obliquely rearward and leftward direction; and a right bank extends in an obliquely rearward and rightward direction which includes a cylinder having a cylinder axis line extending in an obliquely rearward and rightward direction; wherein the left bank and the right bank each include: a cylinder block including the cylinder provided therein; and a cylinder head secured to the cylinder block so as to cover the cylinder along the cylinder axis line and defining a combustion chamber together with the cylinder, a cylinder block including the cylinder provided therein; and a cylinder head secured to the cylinder block so as to cover the cylinder along the cylinder axis line and defining a combustion chamber together with the cylinder, characterized in that the cylinder head including an intake port arranged inward relative to the cylinder axis line in an outboard motor width direction and in communication with the combustion chamber and also including an exhaust port arranged outward relative to the cylinder axis line in the outboard motor width direction and in communication with the combustion chamber; and the outboard motor further comprises: a crankcase including the crankshaft accommodated therein; a left exhaust path arranged outward relative to the crankcase and the left bank in the outboard motor width direction and in communication with the exhaust port in the left bank; a right exhaust path arranged outward relative to the crankcase and the right bank in the outboard motor width direction and in communication with the exhaust port in the right bank; a left catalyst located inside the left exhaust path; and a right catalyst located inside the right exhaust path. a crankcase including the crankshaft accommodated therein; a left exhaust path arranged outward relative to the crankcase and the left bank in the outboard motor width direction and in communication with the exhaust port in the left bank; a right exhaust path arranged outward relative to the crankcase and the right bank in the outboard motor width direction and in communication with the exhaust port in the right bank; a left catalyst located inside the left exhaust path; and a right catalyst located inside the right exhaust path.