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.

Navaandorjiin Jadambaa
Наваандоржийн Жадамбаа
1st Chairman of the State Great Khural
In office 28 November 1924 – 29 November 1924
Preceded by	Bogd Khan (as Khagan) Balingiin Tserendorj (acting)
Succeeded by	Peljidiin Genden
Personal details
Born	1900 Bator-Van, Outer Mongolia, Qing China (now Selenge Province, Mongolia)
Died	1939 (aged 38–39) Mongolia
Political party	Mongolian People’s Revolutionary Party (1921–1928)

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.