In a webbing take-up device, a cylinder includes a housing portion that houses a piston and a guide portion that extends from one end portion in length direction of the housing portion. A pinion is rotatably supported at the guide portion. The piston is guided by the guide portion. A member that houses the piston and a member that rotatably supports the pinion do not accordingly need to be separately provided. An increase in number of components can therefore be suppressed. Positioning of the piston and the pinion can be respectively determined by the cylinder due to the piston and the pinion being provided to the cylinder. Good positioning precision between the piston and the pinion is thereby enabled compared to a case where separate members are used to house the piston and to rotatably support the pinion.
