Santa Ana Chiautempan is a city in Chiautempan Municipality in the south-central part of the Mexican state of Tlaxcala. The city serves as the municipal seat of the municipality, which covers an area of 66.21 km² (25.56 sq mi). At the 2005 census it had a population of 46,776 inhabitants, the fourth-largest community in the state in population (after Villa Vicente Guerrero, Apizaco, and Huamantla). The city lies at the extreme western end of the municipality, which had a census population of 63,300 inhabitants.