A work vehicle, comprising: a power transmission shaft drivable to rotate; a shaft holder holding the power transmission shaft in such a manner that the power transmission shaft is rotatable; and a hydraulically operable section (CL1, CL2, CL3, CL4) configured to operate in response to receiving operating oil, the power transmission shaft including: a shaft groove extending entirely around an outer circumferential portion of the power transmission shaft; an inlet port extending inside the power transmission shaft in a radial direction of the power transmission shaft and connected with the shaft groove; and a supply oil passage extending inside the power transmission shaft in a longitudinal direction of the power transmission shaft and connected with the inlet port inside the power transmission shaft, the shaft holder including: an outer flow path in a shape of a ring around the shaft groove; a first supply port (30a-30d) connected with the outer flow path and configured to receive operating oil; and at least one second supply port extending from the outer flow path to an inner circumferential portion of the shaft holder and communicating with the shaft groove, characterised in that the work vehicle being configured to cause operating oil to be supplied from the first supply port (30a-30d) sequentially through the outer flow path, the at least one second supply port, the shaft groove, the inlet port, and the supply oil passage to the hydraulically operable section (CL1, CL2, CL3, CL4). a power transmission shaft drivable to rotate; a shaft holder holding the power transmission shaft in such a manner that the power transmission shaft is rotatable; and a hydraulically operable section (CL1, CL2, CL3, CL4) configured to operate in response to receiving operating oil, the power transmission shaft including: a shaft groove extending entirely around an outer circumferential portion of the power transmission shaft; an inlet port extending inside the power transmission shaft in a radial direction of the power transmission shaft and connected with the shaft groove; and a supply oil passage extending inside the power transmission shaft in a longitudinal direction of the power transmission shaft and connected with the inlet port inside the power transmission shaft, a shaft groove extending entirely around an outer circumferential portion of the power transmission shaft; an inlet port extending inside the power transmission shaft in a radial direction of the power transmission shaft and connected with the shaft groove; and a supply oil passage extending inside the power transmission shaft in a longitudinal direction of the power transmission shaft and connected with the inlet port inside the power transmission shaft, the shaft holder including: an outer flow path in a shape of a ring around the shaft groove; a first supply port (30a-30d) connected with the outer flow path and configured to receive operating oil; and at least one second supply port extending from the outer flow path to an inner circumferential portion of the shaft holder and communicating with the shaft groove, characterised in that an outer flow path in a shape of a ring around the shaft groove; a first supply port (30a-30d) connected with the outer flow path and configured to receive operating oil; and at least one second supply port extending from the outer flow path to an inner circumferential portion of the shaft holder and communicating with the shaft groove, characterised in that the work vehicle being configured to cause operating oil to be supplied from the first supply port (30a-30d) sequentially through the outer flow path, the at least one second supply port, the shaft groove, the inlet port, and the supply oil passage to the hydraulically operable section (CL1, CL2, CL3, CL4).