The Jōban Line is a railway line in Japan operated by the East Japan Railway Company. The line officially begins at Nippori Station in Arakawa, Tokyo before the line officially ends at Iwanuma Station in Iwanuma, Miyagi. However, following the opening of the Ueno–Tokyo Line, Jōban Line train services originate at Shinagawa or Ueno; likewise, Jōban Line trains continue past Iwanuma onto the Tōhoku Main Line tracks to Sendai. The line approximately parallels the Pacific coasts of Chiba, Ibaraki, and Fukushima Prefectures.

The East Japan Railway Company is a major passenger railway company in Japan, the largest of the seven Japan Railways Group companies. The company name is officially abbreviated as JR-EAST or JR East in English, and as JR Higashi-Nihon in Japanese. The company's headquarters are in Yoyogi, Shibuya, Tokyo, next to Shinjuku Station. It is listed in the Tokyo Stock Exchange, is a constituent of the TOPIX Large70 index, and is one of three Japan Railways Group constituents of the Nikkei 225 index, the others being JR Central and JR West.