Robertsganj, sometimes referred to as Sonbhadra City (Hindi: sōnbhadra nagar), is a city and municipal board located in the Sonbhadra district of Uttar Pradesh, India.

The state’s southeast is where Robertsganj is situated. The administrative center of Sonbhadra District is located in Robertsganj. On March 4, 1989, the southern portion of the Mirzapur district was divided off to form the district of Sonbhadra, with Robertsganj serving as its district headquarters. This region is drained by the rivers Son, Karmnasha, Chandra Prabha, Rihand, Kanhar, Renu, Ghagar, and Belan. Frederick Roberts, 1st Earl Roberts, is honored by the name of the city.