Điện Biên Province in the context of Lai Châu Province

Điện Biên Phủ (Vietnamese: [ɗîənˀ ɓīən fû] , chữ Hán: 奠邊府) is a city in the northwestern region of Vietnam. It is the capital of Điện Biên Province. The city is best known for the decisive Battle of Điện Biên Phủ, which occurred during the First Indochina War of independence against France. The region is a center of ethnic Tai culture. In prior history, the city was formerly called Muang Thaeng.

Điện Biên Phủ lies in Mường Thanh Valley, a 20 km (12 mi) long and 6 km (3.7 mi) wide basin sometimes described as "heart-shaped." It is on the western edge of Điện Biên Province, of which it is the capital, and is only about 10 kilometres (6.2 mi) from the border with Laos.

Tây Bắc (literally "Northwest") is one of the regions of Vietnam, located in the mountainous northwestern part of the country. It consists of four provinces: Điện Biên, Lai Châu, Sơn La and Lào Cai. It has a population of 4.9 million (2022) and it is fully landlocked.

The Mường Thanh Valley is a valley located in the Điện Biên Province of Northwestern Vietnam. The valley is approximately 20 km long by 5 km wide. A heart-shaped basin, the valley is surrounded by a region filled with jungles, rice paddies, and lakes. Located within the Mường Thanh Valley is the city of Điện Biên Phủ. The capital of Điện Biên Province, Điện Biên Phủ, is famous as the site of a decisive battle in 1954 in which French forces were defeated by Việt Minh troops under general Võ Nguyên Giáp.

Mường Lay is a ward (phường) of Điện Biên Province, northwestern Vietnam.

The Standing Committee of the National Assembly promulgated Resolution No. 1661/NQ-UBTVQH15 on the rearrangement of commune-level administrative units of Điện Biên Province in 2025 (the Resolution takes effect from 16 June 2025). Accordingly, Mường Lay Ward was established under Điện Biên Province on the basis of the entire 22.88 km² of natural area and a population of 5,139 from Na Lay Ward; the entire 29.33 km² of natural area and a population of 960 from Sông Đà Ward; the entire 60.46 km² of natural area and a population of 5,535 from Lay Nưa Commune of Mường Lay Town; and the entire 110.00 km² of natural area and a population of 6,574 from Sá Tổng Commune of Mường Chà District.