Economic imperialism is the foreign control of assets and decisions, even when such control exists in practice but not in law. It can occur in both informal, postcolonial settings as well as formal, colonial ones, and involves the one-sided transfer of capital, labour, or natural resources from one nation to another.

In 1921, French Professor Achille Viallate (1866-1943) discussed economic imperialism as a trade and finance phenomenon in terms of "imperialist expansion [...] dictated by the desire of 'the great industrial nations' to find 'outlets both for the utilization of their available capital and for the surplus of their production'."

Scholars have identified five modes of economic imperialism: colonialism, internal colonialism, settler colonialism, investment imperialism, and unequal exchange.

Colonialism is a system of domination characterised by a foreign group's control over another territory, its natural resources, and its people. It is most often applied to the domination of European societies over non-European ones via conquest and settlement from the Age of Discovery in the 15th century to decolonisation in the 20th century, however historical examples also include Europeans colonising other Europeans and non-Europeans colonising other non-Europeans. While colonialism sometimes indirectly led to development dependent on the autonomy/independence of the colonised population and their position in the international division of labour, it was overall harmful due to its role in the history of genocides, famine, and war, and evidenced by the poles of contemporary global inequality. Regions that were relatively rich in 1500 and were subsequently colonised became relatively poor.

Early industrial societies exported their unemployment (caused by technical change and the displacement of small producers) to their colonies, either through settler migration or through enforcing free trade and flooding colonial markets with goods produced in the metropole (causing unemployment in the colony). An example of this was the deindustrialisation of India under British rule. Natural resources from colonies also fueled the metropole's industrial development, and the nature of colonial trade meant colonies were effectively paid for their exports out of their tax revenue, effectively eliminating their export surpluses. This all served to drain wealth from the colonies.

Internal colonialism is the uneven effects of economic development on a regional basis, otherwise known as "uneven development", as a result of the exploitation of minority groups within a wider society which leads to political and economic inequalities between regions within a state. It is "a geographically-based pattern of subordination of a differentiated population, located within the dominant power or country". Internal colonies provide the metropole with accessible, cheap, disposable labour, land, and natural resources.

Historical examples identified by scholars have included the United States and African Americans and Chicanos, the United Kingdom and Ireland, and the Soviet Union and Ukraine.

Settler colonialism is "a specific mode of domination where a community of exogenous settlers permanently displaces to a new locale, eliminates or displaces indigenous populations and sovereignties, and constitutes an autonomous political body". It involves "land confiscation, the expulsion of the indigenous population, and the dispossession of its wealth and property". Settler colonies have also tended to subject indigenous populations to dual labour markets and economic exploitation more often associated with internal colonialism. They typically can develop independently through "accumulation by dispossession".