Line 3 of the Guangzhou Metro is a 65.43-kilometer (40.66 mi) rapid transit line connects Panyu Square to Tianhe Coach Terminal. The entire line, including all track and stations, is located in tunnels. Its 57.93 km (36.00 mi) main branch, excluding the 7.5 km (4.66 mi) branch between Tianhe Coach Terminal and Tiyu Xilu, is now the third longest continuous subway tunnel in the world, and the longest rail tunnel of any kind.

The Guangzhou Metro is the rapid transit system of the city of Guangzhou in the Guangdong Province of China. It is operated by the state-owned Guangzhou Metro Corporation and was the fourth metro system to be built in mainland China, after those of Beijing, Tianjin, and Shanghai.