The Keisei Bus Co., Ltd. is a bus company within the Keisei Group. It was established on 1 October 2003 to inherit all business of the Keisei Electric Railway bus department.

The Keisei Electric Railway Company, Ltd. is a major private railway in Chiba Prefecture and Tokyo, Japan. The name Keisei is the combination of the kanji 京 from Tokyo (東京)and 成 from Narita (成田), which the railway's main line connects. The combination uses different readings than the ones used in the city names. The railway's main line runs from Tokyo to Narita and the eastern suburb cities of Funabashi, Narashino, Yachiyo, and Sakura. Keisei runs an airport limited express train called the Skyliner from Ueno and Nippori to Narita International Airport.