Line 4 of Tianjin Metro (Chinese: 天津地铁4号线; pinyin: Tiānjīn Dìtiě Sì Hào Xiàn) is a metro line in Tianjin.

The south section (Dongnanjiao–Xinxingcun) started operation on 28 December 2021.

[1] OSI: Out-of-station interchange