The Stó꞉lō (/ˈstɔːloʊ/), alternately written as Sto꞉lo, Stó꞉lô, or Stó꞉lõ, historically as Staulo, Stalo or Stahlo, and historically known and commonly referred to in ethnographic literature as the Fraser River Indians or Lower Fraser Salish, are a group of First Nations peoples inhabiting the Fraser Valley and lower Fraser Canyon of British Columbia, Canada, part of the loose grouping of Coast Salish nations. Stó꞉lō is the Halqemeylem word for "river", so the Stó꞉lō are the river people. The first documented reference to these people as "the Stó꞉lō" occurs in Catholic Oblate missionary records from the 1880s. Prior to this, references were primarily to individual tribal groups such as Matsqui, Ts’elxweyeqw, or Sumas.

The first traces of people living in the Fraser Valley date from 4,000 to 10,000 years ago. The Stó꞉lō called this area, their traditional territory, S'ólh Téméxw. The early inhabitants of the area were highly mobile hunter-gatherers. There is archeological evidence of a settlement in the lower Fraser Canyon (called "the Milliken site" after historian August 'Gus' Milliken) and a seasonal encampment ("the Glenrose Cannery site") near the mouth of the Fraser River. Remains of this latter campsite show that in spring and early summer, the people came here to hunt land and sea mammals, such as deer, elk, and seals and, to a lesser extent, to fish for salmon, stickleback, eulachon, and sturgeon and to gather shellfish. Their lives depended on their success at harvesting the resources of the land and the rivers through fishing, foraging, and hunting.

Contemporary Stó꞉lō elders describe their connection to the land in the statement "we have always been here." They tell of their arrival in S'ólh Téméxw as either Tel Swayel ("sky-born" people) or as Tel Temexw ("earth-born" people) and through the subsequent transformations of ancestral animals and fish such as the beaver, mountain goat, and sturgeon. Xexá:ls (transformers) fixed the world ("made it right") and the people and animals in it, creating the present landscape. As Carlson notes:

The Stó꞉lō walk simultaneously through both spiritual and physical realms of this landscape, connected to the Creator through the land itself, as transformed by Xexá:ls.

There is a continuous record of occupation of S'ólh Téméxw by First Nations people dating from the early Holocene period, 5,000 to 10,000 years ago. Two archaeological sites referred to in the Origins section are well documented. Additional archaeological evidence from the early period has been found throughout the region, including sites at Stave Lake, Coquitlam Lake, and Fort Langley.

Many more sites exist that date from the middle Holocene period (c. 5,500–3,000 years ago). Tools found indicate considerable continuity with the early period. One striking feature of this period is the introduction of permanent house sites, showing evidence of cultural transmission from a nomadic to a more sedentary lifestyle between 5,000 and 4,000 years ago. Characteristic of this period were decorative and sculpted stone items, an increasingly complex relationship with the environment, and a more stable and increasingly complex culture. The now extinct Coast Salish woolly dog appeared for the first time during this period.

Among the oldest archaeological digs in Canada is Xá:ytem, at Hatzic, just east of present-day Mission. Initial work on a suburban housing project around a transformer stone aroused the interests of Stó꞉lō archaeologist, Gordon Mohs. The land eventually was transferred to Stó꞉lō governance for heritage purposes. The focus of the site is a large transformer stone which bears the name Xá:ytem. This has come to be used for the ancient village site that has been excavated in the surrounding field. There are two major eras found in the dig, one 3000BP and the other from 5000-9000BP . Both indicate posthole and timber-frame construction and advanced social and economic life. The site was eventually abandoned and covered by flooding and sediment during the ongoing evolution of the Fraser delta.

In the early 21st century, a group of structures known variously as the Fraser Valley Pyramids or Scowlitz Mounds at Harrison Bay, near Chehalis, are under investigation by a joint task force of the Scowlitz First Nation and archaeologists. Little is known about the mounds, which appear to be burial mounds and which contain timber structures to sustain the weight of the mound. Because they are distinct from any other structures anywhere else in the region, the people who made them may not have been forebears of the Stó꞉lō peoples.