Kim Thanh Bridge, International road bridge between Yunnan, China and Lào Cai, Vietnam.

Kim Thanh Bridge (Cầu Kim Thành, 金城大桥) is a prestressed reinforced concrete road bridge over the Red River on the Vietnam–China border, 295 m long with five spans, 21.5 m wide and four traffic lanes. It links the Kim Thanh Industrial and Commercial Zone in Lao Cai city, Vietnam, with the Bac Son Development Zone in Hekou county, Yunnan, China, about 2.5 km upstream from the Lao Cai border gate.

The structure was completed in 2009 after a joint project between Vietnam and China and has connected the two border regions since then. Its construction was a key step in improving transport connections between the countries.

The bridge takes its name from the Kim Thanh Industrial and Commercial Zone on the Vietnamese side, which it links to the Bac Son Development Zone in Hekou. Traffic on its four lanes is freight and cross-border business rather than tourism, and the Chinese name 金城大桥 is written on signage at the crossing.

The bridge is located about 2.5 kilometers from the Lao Cai international border gate and is easily accessible by road from both sides. Visitors should note that crossing requires proper documentation and congestion levels vary depending on the time of day.

The bridge forms part of a larger trade network connecting Vietnam's Hai Phong port with markets in southern China. This route plays an important role in regional commerce and facilitates daily business activities between the two countries.