Morelos, officially the Free and Sovereign State of Morelos, is a landlocked state located in south-central Mexico. It is one of the 32 states which comprise the Federal Entities of Mexico. It is divided into 36 municipalities and its capital city is Cuernavaca.

Morelos is bordered by Mexico City to the north, and by the states of México to the northeast and northwest, Puebla to the east and Guerrero to the southwest.

Morelos is the second-smallest state in the nation, just after Tlaxcala. It was part of a very large province, the State of Mexico, until 1869 when President Benito Juárez decreed that its territory would be separated and named in honor of José María Morelos y Pavón, who defended the city of Cuautla from royalist forces during the Mexican War of Independence. Most of the state enjoys a warm climate year-round, which is good for the raising of sugar cane and other crops. Morelos has attracted visitors from the Valley of Mexico since Aztec times.

The state is also known for the Chinelos, a type of costumed dancer that appears at festivals, especially Carnival, which is celebrated in a number of communities in the state. It is also home to the Monasteries on the slopes of Popocatépetl, a designated World Heritage Site.

Historian Ward Barrett considers that the "region now known as Morelos has a physical unity sufficient to define and set it in strong contrast to other regions of Mexico." Much of this definition comes from its geography, which is a basin into which abundant water flows. The arrival of the Spanish shifted agriculture from subsistence maize production and cotton cultivation to sugar cane and the refining of such into sugar in nearby mills. This system would remain more or less intact until the Mexican Revolution.

Evidence of the first human inhabitants in what is now Morelos dates back to 6000 B.C. and shows these people as nomadic hunters and gatherers in the areas of Yautepec and Chimalacatlan. Other early finds include clay jars and figures in the Gualupita neighborhood of Cuernavaca and three mounds in Santa María Ahuacatitlán, which are probably the remains of houses.

Francisco Plancarte y Navarrete, Cuernavaca's second bishop (1898–1911), wrote Tamoanchan—El Estado de Morelos y El Principio de la Civilizacion en Mexico in 1911. In it, he proposes that the first agriculturally based settlements in Mexico appeared around 1500 B.C. in a place called Tamoanchan which he associates with Morelos. He writes, "1st - That being in the region of Tamoanchan... they fixed the ritual calendar ... 2nd - That Tamoanchan was not very far from Teotihuacan; 3rd - That to go from Tamoanchan to Teotihuacan they passed through Xumiltepec; 4th - That Tepuztecal (sic) and his companions discovered pulque in the Tamoanchan region. But as all these facts happened in... the State of Morelos ... and accordingly that Tamoanchan is not a mythological and fantastic country... but true..."

The earliest identified culture is the Olmec, which was dominant from 200 B. C. to about A.D. 500. Evidence of this culture is found in reliefs such as those in the Cantera Mountain in Chalcatzingo and clay figures.