Coatzacoalcos (Spanish: [koatsakoˈalkos]; formerly known as Puerto México; Nahuatl languages: Koatzakwalko; Zapotec: Niniashi; Popoluca: Puertu) is a major port city in the southern part of the Mexican state of Veracruz, mostly on the western side of the Coatzacoalcos River estuary, on the Bay of Campeche, on the southern Gulf of Mexico coast.

[4] On 23 July 1940, Coatzacoalcos welcomed refugees from the Spanish Civil War who sought asylum in Mexico after travelling across the Atlantic aboard the SS Santo Domingo.

This location has prompted plans for an interoceanic waterway across the Isthmus of Tehuantepec, or for a much expanded railroad system, for over a century.

Four big industrial petrochemical complexes are located near the city (Pajaritos, Cosoleacaque, Morelos and Cangrejera) making it one of the most important concentrations of its kind in the world.

Ferrosur also provides rail service in and out of Coatzacoalcos as far southeast as Las Choapas, to the north and west to Veracruz and Mexico City, as well as to the south over the Tehuantepec route now owned by Ferrocarril Transístmico from Medias Aguas to Salina Cruz in the state of Oaxaca.

[13] Mexican Federal Highway 180 follows the southern shore of the Bay of Campeche through Coatzacoalcos to the Yucatán Peninsula.

Highway 180 and a rail line to Allende have been carried over the Coatzacoalcos River via the 1910 built Coatza I bridge for more than a century.

A second cable stayed bridge known as Coatza II or Antonio Dovalí Jaime was built to the south to carry more road traffic over the river.

[15] A ferry operates between the city of Coatzacoalcos and Allende, which in 2017 was supplemented by a 1.1-kilometre (0.68 mi) underwater tunnel that carries four lanes of traffic.

[4] Coatzacoalcos is also the northern terminus of Mexican Federal Highway 185, which links it with the Pacific Ocean at Salina Cruz, Oaxaca, on the other side of the Isthmus of Tehuantepec.

Coatzacoalcos is the birthplace of actress Salma Hayek; journalist María Antonieta Collins; and footballers Sergio Ramirez, who played for FC Ararat Yerevan, in the Armenian Premier League and José Arturo Rivas, who played for the Tigres de la UANL, in the Primera División de México.

Also, Silviano Delgado Valladolid, who was part of Mexico's National Squad during Barcelona 1992 Olympic Games and played for Toluca F.C., Puebla F.C., Morelia F.C.