Settler colonialism is a process by which settlers exercise colonial rule over a land and its indigenous peoples, transforming the land and replacing its population with settlements and the society of the settlers. Assimilation has sometimes been conceptualized in biological terms such as "breeding of a minority population into a majority"; but in certain cases, such as in some parts of Latin America biological mixing of populations was less problematic.

Settler colonialism is a form of exogenous (of external origin, coming from the outside) domination typically organized or supported by an imperial authority, which maintains a connection or control to the territory through the settler's colonialism. Settler colonialism contrasts with exploitation colonialism, where the imperial power conquers territory to exploit the natural resources and gain a source of cheap or free labor. As settler colonialism entails the creation of a new society on the conquered territory, it lasts indefinitely unless decolonisation occurs through departure of the settler population or through reforms to colonial structures, settler-indigenous compacts and reconciliation processes.

Settler colonial studies has often focused on English-speaking settler colonies in Australia and North America, which are close to the complete, prototypical form of settler colonialism. However, settler colonialism is not restricted to any specific culture, it has been practised by non-Europeans and between different European cultures as in the case of [[Plantations of Ireland|Ireland].

During the 1960s, settlement and colonization were perceived as separate phenomena from colonialism. Settlement endeavours were seen as taking place in empty areas, downplaying the Indigenous inhabitants. Later on in the 1970s and 1980s, settler colonialism was seen as bringing high living standards in contrast to the failed political systems associated with classical colonialism. Beginning in the mid-1990s, the field of settler colonial studies was established^{[page needed]} distinct but connected to Indigenous studies. Although often credited with originating the field in his Settler Colonialism and the Transformation of Anthropology (1999), Australian historian Patrick Wolfe stated that "I didn't invent Settler Colonial Studies. Natives have been experts in the field for centuries." Additionally, Wolfe's work was preceded by others that have been influential in the field, such as Fayez Sayegh's Zionist Colonialism in Palestine (1965), Settler Capitalism by Donald Denoon (1983) and Daiva Stasiulis and Nira Yuval-Davis in Unsettling Settler Societies (1995).^{[page needed]}

Settler colonialism is characterized as both a logic and structure, and not a mere occurrence. Settler colonialism takes claim of environments for replacing existing conditions and members of that environment with those of the settlement and settlers. Intrinsically connected to this is the displacement or elimination of existing residents, particularly through destruction of their environment and society. As such, settler colonialism has been identified as a form of environmental racism.

Wolfe's model of settler colonial theory posits that settler colonialism is categorically distinct from other forms of colonialism by its drive to "eliminate the native", instead of exploiting them. For Wolfe and his "intellectual successor" Lorenzo Veracini, settler colonialism is "structural, eliminatory, and land based, which—they argued—distinguish it from franchise colonialism, which is based on the exploitation of the native population instead." Therefore, colonial settling has been called an invasion or occupation, emphazising the violent reality of colonization and its settling, in contrast to the more domestic meaning of "settling".

According to certain genocide scholars, including Raphael Lemkin – the individual who coined the term genocide – colonization is intimately connected with genocide. Some scholars further describe the process as inherently genocidal, considering settler colonialism to entail the elimination of existing peoples and cultures, and not only their displacement (see genocide, "the intentional destruction of a people in whole or in part").^{[citation needed]} Depending on the definition, for Wolfe settler colonial eliminationism may be enacted by a variety of means, including mass killing of the previous inhabitants, removal of the previous inhabitants and/or cultural assimilation.

However, the opposite argument has been made by Veracini, who argues that all genocide is settler colonial in nature but not all settler colonialism is genocidal. Sai Englert also argues against the Wolfe model, proposing that settler colonies have used both elimination and exploitation in their relations with indigenous peoples, and often transitioned from one to the other: "By assuming that exploitation, by definition, lays outside the realm of its field of study, SCS has privileged the analysis of the Anglo-settler world—primarily North America and Oceania." For him, the specificity of settler colonialism from other forms of colonialism is its social relations of class struggle within settler societies over the distribution of "colonial loot".