The Jōban Line (常磐線, Jōban-sen) is a railway line in Japan operated by East Japan Railway Company (JR East). It begins at Nippori Station in Taitō, Tokyo and follows the Pacific coasts of Chiba, Ibaraki, and Fukushima Prefectures before the line officially ends at Iwanuma Station in Iwanuma, Miyagi. However, most trains originate at Ueno rather than Nippori; likewise, many trains continue past Iwanuma onto the Tōhoku Main Line tracks to Sendai.

The name "Jōban" is derived from the names of the former provinces of Hitachi (常陸) and Iwaki (磐城), which the line connects to Tokyo.

As of August 2014, two segments of the Joban Line are closed in the wake of the 2011 Tōhoku earthquake and tsunami and Fukushima Daiichi nuclear disaster. The segment between Tatsuta and Haranomachi, which runs through the exclusion zone surrounding the Fukushima Daiichi nuclear meltdown, is closed indefinitely, while the segment between Hamayoshida and Sōma is under reconstruction and served by an interim bus service. JR East is currently inspecting the segments between Hirono and Tomioka and between Namie and Haranomachi in preparation for the surrounding areas being cleared for re-settlement, and plans to reconstruct the track and stations between Hamayoshida and Komagamine in new positions located farther inland, targeting completion by 2017. As of January 31, 2015, sections between Tatsuta and Haranomachi are replaced by a bus service.