The Loop line of Chongqing Rail Transit is a rapid transit loop line in Chongqing, China. The line is also known as Line 0.

The Chongqing Rail Transit is the rapid transit system in the city of Chongqing, China. In operation since 2005, it serves the transportation needs of the city's main business and entertainment downtown areas and inner suburbs. As of December 2023, CRT consisted of eleven lines, with a total track length of 523.68 km (325 mi). Lines 1, 4, 5, 6, 9, 10, 18, the Loop line and Jiangtiao line are conventional heavy-rail metro lines, while Lines 2 and 3 are high-capacity monorails. To keep up with urban growth, construction is under way on Line 18 and several other lines, in addition to extensions to Lines 5, 6 and 10.