Bihar jiha ce, da ke a Gabashin ƙasar Indiya. Tana da yawan fili kimanin kilomita murabba’i 94,163 da yawan jama’a 104,099,452 (in ji ƙidayar shekarar 2011). Jihar tarayyar Indiya ce daga shekara ta 1950. Babban birnin jihar da birnin mafi girman jihar Patna ne. Phagu Chauhan shi ne gwamnan jihar. Jihar Bihar tana da iyaka da jihohin uku (Uttar Pradesh a Yamma, Bengal ta Yamma a Gabas, Jharkhand a Kudu) da ƙasar ɗaya (Nepal a Arewa).