Gangapur Athar is a village in Sarairanjan tehsil in district of Samastipur, Bihar, India. As per the data provided by Census of India in 2011, total population of Gangapur Athar was 9,408 which includes 4,887 males and 4,521 females. Gangapur Athar covers 422 ha area. Pincode of Gangapur Athar is N/A.