An eccentric butterfly valve includes a valve body formed therein with an internal flow passage extending in a direction of the flow passage axis, a valve member supported by the valve body through valve stems to be rotatable about a rotation axis perpendicular to the flow passage axis, and a seat ring attached to an inner periphery of the internal flow passage. The valve stems include a first valve stem and a second valve stem. The valve body is formed therein with a stem through-hole through which the first valve stem is inserted and a stem bottomed-hole supporting the second valve stem. The valve member is provided with a fitting hole and an engagement groove. A fitting portion provided at the first valve stem is fitted into the fitting hole and an engagement portion provided at the second valve stem is inserted into the engagement groove.