Line S3 of the Chengdu Metro (simplified Chinese: 成都地铁S3线; traditional Chinese: 成都地鐵S3線), also known as Ziyang Line (Chinese: 资阳线), is a rapid transit line in Sichuan Province, China.

The line is 38.7 km long and connects Futian in Chengdu to Ziyang Bei Station in Ziyang;[2][4] the line opened on 29 September 2024.

The line will have both underground and ground level sections.

[5] Total investment for the line is 14.93 billion CNY.

[6] 40% is paid by Chengdu; relocation fee in Ziyang is paid by Ziyang Government; 54.1% left is mortgage from bank.