Line 9 is a rapid transit line of the Tianjin Metro. It spans 52.8 km (32.8 mi) with 21 stations, connecting the urban area of Tianjin with Binhai New Area, a new area within the jurisdiction of Tianjin Municipality. The one-way journey time is approximately one hour.

The Tianjin Metro or Tianjin Rail Transit is the rapid transit system in the city of Tianjin, which was the second city in mainland China after Beijing to operate a subway system. First opened in 1984, the system currently has 10 operating lines and 217 stations spanning 301 km (187.0 mi).