Topoxte (/tɒpɒʃtˈɛ/) (or Topoxté in Spanish orthography) is a pre-Columbian Maya archaeological site in the Petén Basin in northern Guatemala with a long occupational history dating as far back as the Middle Preclassic. As the capital of the Kowoj Maya, it was the largest of the few Postclassic Mesoamerican sites in the area. Topoxte is located on an island on Yaxha Lake across from the important Classic period center of Yaxha.

Topoxte was named by Teobert Maler in 1904; the name means "seed of the Ramón tree." There is no record of the name Topoxte prior to this. The Ramón tree, commonly known as breadnut, was an important component of the ancient Maya diet. Prior to this the site was known as Islapag, as noted in 1831 by Juan Galindo in his report to the Society of Antiquaries of London.

Topoxte occupies five of a cluster of six islands at the western end of Lake Yaxha in the municipality of Melchor de Mencos in the eastern part of the Guatemalan department of Petén. Due to the extreme fluctuations of the water level of the lake, these islands can sometimes become landlocked.

The principal occupation existed on the three islands named Topoxte, Cante and Paxte. When the water level was higher the lake was connected via a natural canal to the neighbouring Lake Sacnab, which lies to the east. Three smaller lakes lie to the west, from west to east they are lakes Chompoxte, Colorada and Coloradita.

The island of Topoxte lies at an altitude of 168 metres (551 ft) above sea level. The island is formed from limestone with the highest elevation in the northern part of the island, sloping gently down towards the south.

The closest town is Flores, the capital of the Petén department, 52 kilometres (32 mi) to the west as the crow flies. Topoxte is 29 kilometres (18 mi) west of the international border with Belize and about 80 kilometres (50 mi) south of the international border with Mexico. It is 28 kilometres (17 mi) northeast of Zacpeten, another important Kowoj settlement.

Archaeological investigations have revealed that the site was occupied from the Middle Preclassic right through to the Late Postclassic. Obsidian from the Ixtepeque source started to be used from the Terminal Classic onwards and is used as a diagnostic marker for dating finds to the later periods of occupation at the site, when Ixtepeque became the principal source of obsidian for Topoxte and the wider Maya lowlands.

The site was abandoned at the end of the Classic period (ca. 900) and reoccupied during the Postclassic at approximately 1100. After being inhabited for a further three and a half centuries it may finally have been abandoned around 1450, although this has now been challenged.