To provide a hydraulic PTO clutch with an inertia braking mechanism capable of simplifying a structure, reducing the number of components, and achieving cost reduction.

In this hydraulic PTO clutch having a clutch mechanism 8 for disconnecting/connecting a PTO propeller shaft 3 supported in a transmission case 1 and a PTO transmission shaft 9 to which power is transmitted from the PTO propeller shaft 3, and an inertia braking mechanism 19 for braking the PTO transmission shaft 9 by elastically pressing a braked plate 21 capable of approaching to and separating from a brake disc 20 fixed and held on the transmission case 1, and mounted on a clutch body 13 in a state of being rotated integrally with the clutch body 13 connected with the PTO transmission shaft 9, to the brake disc 20 through a plurality of pins mounted at intervals in the circumferential direction by returning motion of a clutch piston 18 when the clutch is disconnected, the plurality of pins 24 are supported slidably to the clutch body 13 at a radial outer side position of a cylinder chamber 14 of the clutch piston 17.