Line 11 is a rapid transit line of the Suzhou Metro system. It was formerly known as Line S1 during planning and construction. Construction started on November 27, 2018. It opened on June 24, 2023. The line uses driverless 6-car Class B rolling stock operating up to . Partial through-running with Line 3 began on December 23, 2023, and full through-running began on June 29, 2024.
Running west-east, the line mainly serves the urban area of Kunshan, and connects it to Suzhou Industrial Park in the west and nearby Shanghai in the east via a transfer at Huaqiao station to Line 11 of Shanghai Metro. The line is the first metro line in downtown Kunshan.
Through service between Line 3 and Line 11 started on December 23, 2023.