Tarhasi Block is one of the administrative blocks of Palamu district, Jharkhand state, India situated in the bank of amanat river.
At the time of the 2011 census, Tarhasi block had a population of 81,297. Tarhasi block had a sex ratio of 940 females per 1000 males and a literacy rate of 63.56%: 74.47% for males and 51.94% for females. 13,717 (16.87%) were under 7 years of age. The entire population lived in rural areas. Scheduled Castes and Scheduled Tribes were 23,129 (28.45%) and 1,906 (2.34%) of the population, respectively.