Vientiane (Lao: ວຽງຈັນ, romanized: Wiang Chan, pronounced [wíaŋ tɕàn]) is the capital and largest city of Laos. Situated on the banks of the Mekong River at the Thai border, it comprises the five urban districts of Vientiane Prefecture and had a population of 840,000 as of the 2023 Census. Established as the capital of the Lan Xang Kingdom in 1563, Vientiane served as the administrative center during French rule and retains colonial-era architecture alongside Buddhist landmarks such as Pha That Luang, a national symbol of Buddhism, and Haw Phra Kaew, which once housed the Emerald Buddha until its 18th-century relocation to Thailand.

The city functions as Laos’ political, economic and transportation hub, emphasizing regional connectivity through infrastructure projects like the Laos-China Railway. This railway, a component of China’s Belt and Road Initiative, terminates in Vientiane after linking Kunming, China, and is slated to connect to Thailand’s rail network via the Mekong Railway Bridge.