Founded: 1881 (then named K. Hattori & Co.) | Founding place: Tokyo, Japan | Founded by: Kintarō Hattori | Current headquarters: Tokyo, Japan | Owned by: privately held (by the Hattori family) | Official name:
- K. Hattori & Co. (1881-1917)
- K. Hattori & Co., Ltd. (1917-1983), first with the brand name Seikosha, and from 1924 with the brand name Seiko
- Hattori Seiko Co., Ltd. (1983-1990)
- Seiko Corporation (1990-2007)
- Seiko Holdings Corporation (2007-2022)
- Seiko Group Corporation (since 2022)