To provide a fluid pressure motor and a transmission, in which a shaft can be easily exchanged.

The fluid pressure motor and the transmission are provided with a case 1 capable of storing fluid, a movable swash plate axial piston pump 2 to be rotatably placed in contact with and project an input shaft 12 with the case 1, a swash axial piston cylinder 3 having a rotation cylinder 4 rotatably and closely penetrating the case 1, having a plurality of cylinders 35 installed around the rotation cylinder 4 from the case 1, and rotating the rotation cylinder 4 by inputting pressure fluid from a pump 2 into the cylinders 35, and an output shaft 10 inserted in the rotation cylinder 4. A clearance 70 is provided between the rotation cylinder 4 and the output shaft 10. The output shaft 10 is supported by two-point mounting on the rotation cylinder 4.