A cylinder device includes an annular cushion ring that prevents collision between the cylinder head and the rod head at stroke end during contraction. The cushion ring is formed by linking a plurality of ring segments in a circumferential direction so as to have an annular shape. The ring segments have a main body portion and linkage portions formed on both ends of the main body portion in the circumferential direction, the linkage portions linking the neighboring ring segments. The linkage portions of the neighboring ring segments are mutually overlapped in an axial direction of the cushion ring and linked such that relative movement in a radial direction of the cushion ring is restricted.