A work vehicle, comprising: an engine; a transmission configured to convert the driving force from the engine; a hydraulic oil supply circuit configured to supply hydraulic oil to the transmission; a hydraulic oil warming circuit configured to warm up the hydraulic oil; and a control unit configured to control the transmission, the hydraulic oil supply circuit, and the hydraulic oil warming circuit, the transmission including: a hydraulic clutch (CF, CR, CH, CL, Cm1, Cm2); and a clutch control valve (VF, VR, VH, VL, Vm1, Vm2) configured to control a pressure of the hydraulic oil supplied to the hydraulic clutch (CF, CR, CH, CL, Cm1, Cm2) according to a command from the control unit, wherein the control unit is configured to output a warming up command to cause the warming up function to be performed when the control unit determines that the temperature of the hydraulic oil is low; and the hydraulic oil warming circuit is configured to warm up the hydraulic oil by causing a pressure loss in a flow path for the hydraulic oil wherein the hydraulic oil supply circuit includes a connection circuit connected to the clutch control valve (VF, VR, VH, VL, Vm1, Vm2); and a transmission pump, characterized in that the hydraulic oil warming circuit includes: a logic valve; and a pilot circuit for the logic valve, the logic valve including: a P port connected to a hydraulic circuit from the transmission pump; and an R port connected to the connection circuit, wherein, upon receipt of the warming up command, the hydraulic oil warming circuit is configured to raise the hydraulic pressure in the pilot circuit, generate a pressure difference between the hydraulic pressure at the P port and the hydraulic pressure at the R port, and warm up the hydraulic oil by flowing the hydraulic oil from the P port to the R port using the pressure loss due to the pressure difference. an engine; a transmission configured to convert the driving force from the engine; a hydraulic oil supply circuit configured to supply hydraulic oil to the transmission; a hydraulic oil warming circuit configured to warm up the hydraulic oil; and a control unit configured to control the transmission, the hydraulic oil supply circuit, and the hydraulic oil warming circuit, the transmission including: a hydraulic clutch (CF, CR, CH, CL, Cm1, Cm2); and a clutch control valve (VF, VR, VH, VL, Vm1, Vm2) configured to control a pressure of the hydraulic oil supplied to the hydraulic clutch (CF, CR, CH, CL, Cm1, Cm2) according to a command from the control unit, wherein the control unit is configured to output a warming up command to cause the warming up function to be performed when the control unit determines that the temperature of the hydraulic oil is low; and the hydraulic oil warming circuit is configured to warm up the hydraulic oil by causing a pressure loss in a flow path for the hydraulic oil wherein the hydraulic oil supply circuit includes a connection circuit connected to the clutch control valve (VF, VR, VH, VL, Vm1, Vm2); and a transmission pump, a hydraulic clutch (CF, CR, CH, CL, Cm1, Cm2); and a clutch control valve (VF, VR, VH, VL, Vm1, Vm2) configured to control a pressure of the hydraulic oil supplied to the hydraulic clutch (CF, CR, CH, CL, Cm1, Cm2) according to a command from the control unit, wherein the control unit is configured to output a warming up command to cause the warming up function to be performed when the control unit determines that the temperature of the hydraulic oil is low; and the hydraulic oil warming circuit is configured to warm up the hydraulic oil by causing a pressure loss in a flow path for the hydraulic oil wherein the hydraulic oil supply circuit includes a connection circuit connected to the clutch control valve (VF, VR, VH, VL, Vm1, Vm2); and a transmission pump, characterized in that the hydraulic oil warming circuit includes: a logic valve; and a pilot circuit for the logic valve, a logic valve; and a pilot circuit for the logic valve, the logic valve including: a P port connected to a hydraulic circuit from the transmission pump; and an R port connected to the connection circuit, wherein, upon receipt of the warming up command, the hydraulic oil warming circuit is configured to raise the hydraulic pressure in the pilot circuit, generate a pressure difference between the hydraulic pressure at the P port and the hydraulic pressure at the R port, and warm up the hydraulic oil by flowing the hydraulic oil from the P port to the R port using the pressure loss due to the pressure difference. a P port connected to a hydraulic circuit from the transmission pump; and an R port connected to the connection circuit, wherein, upon receipt of the warming up command, the hydraulic oil warming circuit is configured to raise the hydraulic pressure in the pilot circuit, generate a pressure difference between the hydraulic pressure at the P port and the hydraulic pressure at the R port, and warm up the hydraulic oil by flowing the hydraulic oil from the P port to the R port using the pressure loss due to the pressure difference.