| Navaandorjiin Jadambaa | |
| Order: | 1st Chairman of the State Great Khural |
| Term Start: | 28 November 1924 |
| Term End: | 29 November 1924 |
| Predecessor: | Bogd Khan |
| Successor: | Peljidiin Genden |
| Birth Date: | 1900 |
| Birth Place: | Bator-Van, Outer Mongolia, Qing China |
| Death Date: | 1939 (aged 38–39) |
| Death Place: | Mongolia |
| Party: | Mongolian People’s Revolutionary Party (1921–1928) |
| Native Name Lang: | mn |
Navaandorjiin Jadambaa (Mongolian: Наваандоржийн Жадамбаа; 1900–1939) was the first republican Head of State of Mongolia. He became Acting Chairman of the State Great Hural in November 1924 following the death of the Bogd Khan, as he was replaced by Peljidiin Genden only a day later.
Usually a regency would follow the death of the Bogd Khan until his reincarnation had reached his majority; however, in this case the search for the reincarnation of the Bogd Khan was banned and the country has maintained a republican constitution ever since.