The Batong Line of the Beijing Subway (Chinese: 北京地铁八通线; pinyin: Běijīng dìtiě Bātōng xiàn) is an east–west rapid transit line in eastern Beijing. It extends Line 1 further east from Sihui in Chaoyang District to Universal Resort in Tongzhou District. Through operation with Line 1 started on August 29, 2021. The Batong Line derives its name by combining the first character of Bawangfen (八王坟), another name for Sihui, and Tongzhou (通州), the eastern suburban district of Beijing which the line serves.