Comalcalco is an ancient Maya archaeological site in the State of Tabasco, Mexico, adjacent to the modern city of Comalcalco and near the southern coast of the Gulf of Mexico. It is the only major Maya city built with bricks rather than limestone masonry and was the westernmost city of the Maya civilisation. Covering an area of 7 km² (2.7 sq mi), Comalcalco was founded in the Late Classic period and may have been a satellite or colony of Palenque based on architectural similarities between the two. The city was a center of the Chontal Maya people.

The name is linked to the adjacent modern city of Comalcalco and derives from the Nahuatl words comalli (comales) calli (house) and the locative co, literally meaning "At the House of the Comales" or "Place of the House of the Comales". This name is a reference to the bricks of the ruined Maya site, which later people thought resembled comales. The ancient place name associated with Comalcalco is Joy Chan pronounced [hoj tʃan], (also spelled Hoi Chan), which means "round sky" or "clouded sky".

Located in the Chontalpa region on an extensive alluvial plain once covered by low evergreen rainforest interspersed with mangrove swamps, Comalcalco lies 2 km (1.2 mi) west of the modern city of Comalcalco on a small rise surrounded by lowlands. It is 51 km (32 mi) from the city of Villahermosa, and approximately 100 mi (160 km) north of Palenque. Before modern times the important Mezcalapa River flowed 900 m (3,000 ft) east of the main buildings in the site.

The city's strategic placement on the old Mezcalapa River meant that Comalcalco controlled the important trading link between Yucatán and the Gulf Coast and the highlands of Chiapas and Guatemala. Archaeologist George F. Andrews of the University of Oregon believes that since Comalcalco was in the largest cacao production zone in Tabasco, it must have been involved in the distribution of this commodity.

Comalcalco was also an important centre of clay figurine production and commerce between 600 and 1000 CE In and around the site, archaeologists have found identical clay moulds and figures, as well as tools, pit kilns and dumping grounds, indicating standardized mass production. Figurines found on Jaina Island, approximately 350 km (220 mi) away on the Yucatán Peninsula, use clay with the same chemical composition as those of Comalcalco. Unlike the funerary objects used on Jaina Island, the figurines of Comalcalco seemed to be meant for daily use. Certain representations appear more frequently in the ceremonial core (rulers, dwarfs, articulated figures), while others (women) are more common in residential areas.

The site reached its peak during the classic period in around 500 CE, although the area had been inhabited long before this date. The oldest item found on the site has been dated to August 10, 561 CE.

The only known ruler of Comalcalco was Ox Balam, who appears in an inscription from the Tortuguero archaeological site. According to that text, Ox Balam was defeated by Tortuguero's Balam Ahau on December 20, 649 CE. In later times, Comalcalco used the emblem glyph [de; fr; ja] of B'aakal associated with Palenque and Tortuguero, presumably due to conquest by the latter polity.

A tomb found in Temple II (see below) references numerous late 8th century rituals associated with rain deities. The city possibly suffered from the severe drought that may have occurred throughout the region, and may have been at least partly responsible for the Classical Maya collapse.