Tonatico Municipality is one of the municipalities of the State of Mexico, in Mexico located 153 kilometers from Mexico City, 105 from Cuernavaca, 84 from Toluca, 68 from Taxco and 5 from Ixtapan de la Sal. Tonatico, of Náhuatl origin, is from the Náhuatl word tonatihco, place of the sun.

Prehistoric animal remains and cave paintings have been found in the area around the modern town.

According to legend, the Aztec emperor Axayacatl conquered the area, then known as Tenati-Tlan, "behind the walls", which had by that time been populated for a few thousand years, and founded Tonatiuh-Co, which had the same borders as the current town. However, no records of this exist. Tonatiuhco was grouped under a tributary province centered at Ocuilan. The town produced small amounts of high quality salt, which it paid in tribute to the Aztec Empire.

The region had been originally populated by the Matlatzincas and Chontales, but at the time of the Spanish Conquest the area belonged to Tlatoani Axayacatzin of Cuahnahuac (present-day Cuernavaca). In 1521 Hernán Cortés sent Andrés de Castro to keep the local peoples from supporting Cuauhtémoc and to subdue the area. Don Gaspar Alonso, a conquistador, forsook his heritage and sided with the natives of Tonatico, taking on the name of Tlachcolcatcal or Tlacatecutli. He most likely died in the town after the Spanish conquest.

In 1525, the Spanish founded the modern town, modifying the indigenous name to Tonaltinco or Tonaltiunco. A few years later, Franciscan friars came to evangelize the area. At the same time, a statue of the Virgin Mary arrived, now called Our Lady of Tonatico. The miracles this statue was credited with led to conflicts with the nearby town of Ixtapan de la Sal. However, the town eventually came under the control of Ixtapan de la Sal in 1553.

During the Mexican War of Independence, both Hermenegildo Galeana and Pedro Ascencio de Alquisiras were active in this area. In 1863, Don Teodoro Estrada and Don Fructuoso Vázquez fought here against the French. In 1870, the town became the seat of the current municipality of Tonatico, though the territory it then governed was only about half the size of its historical extent. The Liberation Army of the South (Zapatistas) were active here, first burning the municipal library in 1912, attacking federal troops in the main church and ultimately expelling federal troops from the town in 1916. Tonatico's annual Passion Play was inaugurated during Holy Week 1940; in the same year, the Feria del Calvario (Calvary Festival) began to be held, recurring annually on the third Friday in Lent every year. The 1985 Mexico City earthquake also affected this area as well, damaging the Sanctuary of Our Lady, where the statue of Our Lady of Tonatico is housed.

Tonatico has had a number of notable residents. Teodoro Estrada was born in the nearby town of Zumpahuacan in the State of Mexico. He fought against the French alongside Porfirio Diaz and his performance on the battlefield won him the rank of colonel. Porfirio Diaz had him murdered in Tenancingo. Brigadier General Domitilo Ayala Arenas was born on May 12, 1885, in La Audiencia, Tonatico. He fought with the Liberation Army of the South, next to Emiliano Zapata. He died February 12, 1932, in Mexico City. Don Sebastián Lealba was born in Tonatico on February 26, 1830, and died in Tetipac, Guerrero. He was the leader of the movement which gained municipal independence for Tonatico on April 26, 1908. There is a bust of Don Sebastián in the municipal hall.

Notable landmarks in Tonatico include: