Colonial expansion under the Spanish Empire was initiated by the Spanish conquistadores and developed by the Monarchy of Spain through its administrators and missionaries. The motivations for colonial expansion were trade and the spread of the Christian faith through indigenous conversions. It lasted for over four hundred years, from 1492 to 1898.

Beginning with the 1492 arrival of Christopher Columbus, over nearly four centuries the Spanish Empire would expand across: most of present day Central America, the Caribbean islands, and Mexico; much of the rest of North America including the Southwestern, Southern coastal, and California Pacific Coast regions of the United States; and though inactive, with claimed territory in present day British Columbia Canada; and U.S. states of Alaska, Washington, and Oregon; and the western half of South America. In the early 19th century the revolutionary movements resulted in the independence of most Spanish colonies in America, except for Cuba and Puerto Rico, given up in 1898 following the Spanish-American War, together with Guam and the Philippines in the Pacific. Spain's loss of these last territories politically ended Spanish colonization in America. The cultural influences, though, still remain.