The Narragansett Indians were known to occupy a winter camp in the Great Swamp, within present day South Kingstown.In March of 1638, Rhode Island founder Roger Williams signed an agreement with two Sachems of the Narragansett Tribe, Canonicus and Miantonomoh, establishing the boundaries between the Narragansett Tribe and the Colony of Rhode Island, as well as to purchase Aquidneck Island.

The agreement was signed at Pettaquamscutt Rock, which is now a part of South Kingstown. Twenty years later, on January 20, 1658, Roger Williams again met with the Sachems of the Narragansett Tribe to purchase much of the area that is now present-day Washington County, including South Kingstown, in what is now known as the Pettaquamscutt Purchase of 1658.

This agreement was also signed at Pettaquamscutt Rock.South Kingstown was sparsely populated and mostly inhabited by farmers in the late seventeenth and early eighteenth century, due to the high demand for livestock and produce in Newport, and land speculators who wanted to hold the land to resell when more settlers inevitably came into the area.

Widespread population of the land was discouraged due to a speculation company known as the Atherton Syndicate buying up land to resell, the powerful Narragansett Nation discouraging settlements, and a dispute over the land with neighboring Connecticut. Over time, most of these problems slowly went away with time.

In the late 1660s, the Atherton Syndicate was run off to join Connecticut in its dispute over the territory and eventually going bankrupt. In 1675 the Great Swamp Fight, a battle of King Philip's War fought by the New England Confederation, essentially wiped out the Narragansett. However in retaliation the Narragansett razed most of the settlements in South Kingstown, including Little Rest, the largest.

After the destruction of Little Rest, the land was described as a "desolate wilderness". Finally, in 1723, Connecticut conceded that the territory belonged to Rhode Island, after decades of lobbying before the Court of St James's in London. In the same year, the Rhode Island General Assembly split the town of Kingstown into the towns of North Kingstown and South Kingstown.

The towns were formally incorporated on February 25th, 1723.In 1888 a narrow strip of land running along the eastern bank of the Pettaquamscutt River to the shore of Narragansett Bay was separated from South Kingstown to form the town of Narragansett.