Line 4 of the Hangzhou Metro (Chinese: 杭州地铁四号线; pinyin: Hángzhōu Dìtiě Sìhào Xiàn) is a rapid transit line in Hangzhou.

Phase 1 of the line started operation since 2015.

Running northeast–southwest, the line connects Hangzhou East railway station, Qianjiang New City and Binjiang District.

Part of the line (Qianjiang Road to Shuicheng Bridge) runs along the north bank of Qiantang River.

The second phase of Line 4 is 26 km in length.