On 13th March 1520, Juan Serrano, in command of caravel Santiago, in Magellan´s crew, arrived to a wide estuary and called it "Ría de la Santa Cruz". On 26th August arrived Magellan himself, and slept on the southern coast before crossing the strait. They camped there for two months for a supply of firewood, fish and meat.
In 1862 two missionaires from the anglican mission, fathers Schmidt and Hanziber, settled in the valley then called "Los Misioneros". Muster refers the fact that their efforts to convert the Tehuelche were unsuccessful. The reverends left for the Falkland Islands the following year.
In 1867, J. Mac Dugall, Mrs. Peterson, and J. Hamsen, comamnded by J. H. Gardiner, travelled upstream through river Santa Cruz, by disposition of Piedrabuena, who provided utensiles, horses and provissions for the journey.
At the end of their journey, they discovered the most beautiful lake in the territory, later called Francisco Pascasio Moreno.
Santa Cruz is already known in all seas through the stories of the sailors who imposed the fact that the port was a real natural dock. Attracted by this data, the frigate "Greyhuan" travelled from Brazil to repair the hulk. Once the ship beached in Santa Cruz, it was repaired in a few days by its own crew.
In order to settle sovereignty, in 1873 the Argentine Government sent Comander Lawrence, who installed a captaincy. On 1st December 1879, Comodore Py raised the flag in the summit of Cerro Misioneros.
At the beginning of the eighties, people were invited to settle in distant areas of the country and to become prosperous by toiling the land. Colonists were granted a lot, 500 sheep, 3 mares, 2 cows, a dismountable house, and toiling utensiles. After five continuous years of work, each colonist acquired the land and only had to return the tools and the cattle provided.
Ten families took this challenge, among them Gregorio Albarracín, who had already beed in the war of Paraguay and in the campaign to the wilderness, and don Gregorio Ibáñez, his wife and his five children. Thus started the population of the village.
The port was declared a historical place by decree 12466 on 5th November 1943.
The organization of Puerto Santa Cruz started with a commitee formed by the following members: Pedro Richmond, Frank Lewis, and Adriano Ariani; in 1954 by Modesto Penas, and in 1955 by Adolfo Carlos Oroz, and then by Mario Lourbé.
In 1959 the major was Octaviano Carbone, and then Alberto Ventura; in 1973, Carlos Suárez; and on 24th March 1976, the municipality was taken by prefect Angel Brana, and then by Aldo Horacio Martínez.
In 1983 Roberto José Victoria won the elections, and in December 1987, Marco Luis Marinkovic.
Since 1991, the major has been Mr. Aníbal Ernesto Pernas.