Rajauli is a tehsil, block and subdivision (sub–district) in Nawada district of Magadh division of the Indian state of Bihar. The tehsil of Rajauli is located at a distance of about 30 kilometres (19 mi) from Nawada city on National Highway 20 and is situated on the bank of Dhanarjay river. Rajauli, a Scheduled Caste (SC) reserved Assembly Constituency (AC) seat, had a total of 302900 electors during the 2015 Bihar Legislative Assembly election. Rajauli subdivision consists of 95 panchayats and 688 revenue villages while Rajauli block consists of 17 panchayats and 169 revenue villages.

Nawada district is one of the thirty-eight districts of the Indian state of Bihar. Nawada is its administrative headquarters. The district is the easternmost district of the Magadh division, one of the nine administrative divisions of Bihar. The area of the modern district was historically part of the Magadha, Shunga and Gupta empires. Koderma and Giridih districts of the state of Jharkhand lie on the southern border of the district; it also shares borders with the Gaya, Nalanda, Sheikhpura, and Jamui districts of Bihar.