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. Assuming office at the age of 24, he would hold the record for youngest non-royal head of state until Jean-Claude Duvalier became president of Haiti in 1971. 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.