El Paso–Juárez in the context of "El Paso"

The international boundary separating Mexico and United States extends from the Pacific Ocean to the Gulf of Mexico. The border traverses a variety of terrains, ranging from urban areas to deserts. It is the most frequently crossed border in the world, with approximately 350 million documented crossings annually. Illegal crossing of the border to enter the United States has caused the Mexico–United States border crisis. It is one of two international borders that the United States has, the other being the northern Canada–United States border; Mexico has two other borders: with Belize and with Guatemala.

Four American Sun Belt states border Mexico: California, Arizona, New Mexico and Texas. One definition of Northern Mexico includes only the six Mexican states that border the U.S.: Baja California, Chihuahua, Coahuila, Nuevo León, Sonora and Tamaulipas. The total length of the continental border is 3,145 kilometers (1,954 miles). From the Gulf of Mexico, it follows the course of the Rio Grande (Río Bravo del Norte) to the border crossing at Ciudad Juárez, Chihuahua, and El Paso, Texas. Westward from El Paso–Juárez, it crosses vast tracts of the Chihuahuan and Sonoran deserts to the Colorado River Delta and San Diego–Tijuana, before reaching the Pacific Ocean.

El Paso is a city in and the county seat of El Paso County, Texas, United States. It is the 22nd-most populous city in the U.S., sixth-most populous city in Texas, and the most populous city in West Texas with a population of 678,815 at the 2020 census, while the El Paso metropolitan area has an estimated 879,000 residents.

El Paso stands on the Rio Grande across the Mexico–United States border from Ciudad Juárez, the most populous city in the Mexican state of Chihuahua. On the U.S. side, the El Paso metropolitan area forms part of the larger El Paso–Las Cruces combined statistical area with Las Cruces, New Mexico. These three cities form a combined international metropolitan area sometimes referred to as the Paso del Norte or the Borderplex, a region of 2.7 million people which constitutes the largest bilingual and binational workforce in the Western Hemisphere.

Ciudad Juárez (US: /sjuːˌdɑːd ˈhwɑːrɛz/ sew-DAHD HWAR-ez; Spanish: [sjuˈðað ˈxwaɾes] ; "Juárez City"), commonly referred to as just Juárez (Lipan: Tsé Táhú'ayá), is the most populous city in the Mexican state of Chihuahua. It was known until 1888 as El Paso del Norte ("The North Pass").

It is the seat of the Juárez Municipality with an estimated metropolitan population of 2.5 million people. Juárez lies on the Rio Grande (Río Bravo del Norte), south of El Paso, Texas, United States. Together with the surrounding areas, the cities form El Paso–Juárez, the second largest binational metropolitan area on the Mexico–U.S. border (after San Diego–Tijuana), with a combined population of over 3.4 million people.