The Yokohama Line is a Japanese railway line of the East Japan Railway Company connecting Higashi-Kanagawa Station in Yokohama, Kanagawa and Hachiōji Station in Hachiōji, Tokyo. The line forms part of what JR East refers to as the "Tokyo Mega Loop" around Tokyo, consisting of the Keiyo Line, Musashino Line, Nambu Line, and Yokohama Line. The line's name comes from the section between Nagatsuta and Higashi-Kanagawa that runs through the city of Yokohama. Nicknamed the Hama-sen (浜線) by locals, the line serves commuters in the southwestern suburbs of Tokyo and northeastern suburbs of Yokohama.

The Keiyō Line is a railway line connecting Tokyo and Chiba in Japan, paralleling the edge of Tokyo Bay. It is operated by the East Japan Railway Company. The line forms part of what JR East refers to as the "Tokyo Mega Loop" (東京メガループ) around Tokyo, consisting of the Keiyō Line, Musashino Line, Nambu Line, and Yokohama Line. It provides the main rail access to Tokyo Disney Resort and the Makuhari Messe exhibition center.