| Gender | Male |
|---|---|
| Meaning | Different meanings depending on the kanji used |
| Origin | Japanese |
Teiichi (written: 貞一) is a masculine Japanese given name. Notable people with the name include:
- Teiichi Matsumaru (松丸 貞一, 1909–1997), Japanese footballer
- Teiichi Nishi (西 貞一, 1907–2001), Japanese sprinter
- Teiichi Okano (岡野 貞一, 1878–1941), Japanese composer
- Teiichi Suzuki (鈴木 貞一, 1888–1989), Japanese general
- Teiichi Yoshimoto (吉本 貞一, 1887–1945), Japanese general
Fictional characters
- Teiichi Niiya (新谷 貞一), protagonist of the manga series Dusk Maiden of Amnesia