A sheet transport device includes a transport roller which transports a sheet, a cover which covers the transport roller, a pinch roller attached to the cover via a shaft facing the transport roller, and a regulation member projecting from a facing surface, facing the transport roller, of the cover and configured to regulate a movement of the shaft in an extending direction of the shaft. The regulation member includes a surface which extends along the extending direction of the shaft, a first end portion fixed to the cover, and a second end portion which faces an end face of the shaft, and is located closer to the end face of the shaft than the first end portion in the extending direction of the shaft.