Mictlantecuhtli, meaning "Lord of Mictlan," is the Olman God of Death and the Underworld.

In Olman mythology, Mictlantecuhtli was God of the dead and the king of "Mictlan," the Olman underworld. He was one of the principal Olman gods and the most prominent of several gods and goddesses of death and the underworld. The worship of Mictlantecuhtli sometimes involved ritual cannibalism, with human flesh being consumed in and around the temple.

Olman legend has it; Mictlantecuhtli dwelt with his wife and his pet dog in a windowless house in Mictlan. Mictlantecuhtli and his wife were the opposites and complements of the deities of life.

Mictlantecuhtli was associated with spiders, owls, bats, the eleventh hour and the northern compass direction, known as Mictlampa, the region of death. He was one of only a few deities held to govern over all three types of souls identified by the Olman, who distinguished between the souls of people who died normal deaths (of old age, disease, etc.), heroic deaths (e.g. in battle, sacrifice or during childbirth), or non-heroic deaths.

Mictlantecuhtli was the god of the day sign Itzcuintli, "the Dog," one of 20 such signs recognised in the Olman calendar, and was regarded as supplying the souls of those who were born on that day. He was seen as the source of souls for those born on the sixth day of the 13-day week and was the fifth of the nine Night Gods.

He was also the secondary Week God for the tenth week of the twenty-week cycle of the calendar, joining the sun god Tōnatiuh to symbolise the dichotomy of light and darkness.