Ka River (ngam anndiraa kadi Gulbin Ka River) woni maayo nder fombina lesdi Nigeria. Ko fuɗɗii e nder Zamfara State, ɗum waɗi ko e 250 km (160 mi) hirnaange haa dow lesdi Kebbi to ɗum hawti e maayo Sokoto ko e 100 km (62 mi) haa worgo Birnin Kebbi, ɓaawo ɓaawo ɓeydaaki nder maayo Niger.