Santiago (/ˌsæntiˈɑːɡoʊ/ SAN-tee-AH-goh, US also /ˌsɑːn-/ SAHN-, Spanish: [sanˈtjaɣo]), also known as Santiago de Chile (Spanish: [sanˈtjaɣo ðe ˈtʃile] ^ⓘ), is the capital and largest city of Chile and one of the largest cities in the Americas. Located in the Chilean Central Valley, it anchors its namesake Santiago Metropolitan Region representing 40% of Chile's total population. Most of the city is situated between 500–650 m (1,640–2,133 ft) above sea level.

Founded in 1541 by the Spanish conquistador Pedro de Valdivia, Santiago has served as the capital city of Chile since colonial times. The city features a downtown core characterized by 19th-century neoclassical architecture and winding side streets with a mix of Art Deco, Gothic Revival, and other styles. Santiago's cityscape is defined by several standalone hills and the fast-flowing Mapocho River, which is lined by parks such as Parque Bicentenario, Parque Forestal, and Parque de la Familia. The Andes Mountains are visible from most parts of the city and contribute to a smog problem, particularly during winter due to the lack of rain. The outskirts of the city are surrounded by vineyards, and Santiago is within an hour's drive of both the mountains and the Pacific Ocean.

Santiago is the political and financial center of Chile and hosts the regional headquarters of many multinational corporations and organizations. The Chilean government's executive and judiciary branches are based in Santiago, while the Congress mostly meets in nearby Valparaíso.

The name Santiago was chosen by the Spanish conqueror Pedro de Valdivia when he founded the city in 1541 as "Santiago del Nuevo Extremo," in reference to his home region of Extremadura and as a tribute to James the Great, the patron saint of Spain. The saint's name appears in various forms in Spanish, such as Diego, Jaime, Jacobo, or Santiago, with the latter derived from the Galician evolution of Vulgar Latin Sanctu Iacobu. Allegedly, there was no indigenous name for the area where Santiago is located, but the Mapuche language uses the adapted name Santiaw.

In Chile, several entities share the name Santiago, which can often lead to confusion. The commune of Santiago, also referred to as Santiago Centro, is an administrative division encompassing the area occupied by the city during colonial times. It is governed by the Municipality of Santiago and led by a mayor. This commune is part of Santiago Province, which is headed by a provincial delegate appointed by the President of the Republic, and it is also part of the Santiago Metropolitan Region, governed by a popularly elected governor.

When the term Santiago is used without further clarification, it typically refers to Gran Santiago ('Greater Santiago'), the metropolitan area characterized by continuous urban development. This area includes the commune of Santiago and over 40 other communes, encompassing much of Santiago Province and parts of neighboring provinces. The definition of the metropolitan area has evolved over time as the city has expanded, incorporating smaller cities and rural areas.

Residents of the city and region are referred to as santiaguinos (for males) and santiaguinas (for females).

Archaeological evidence suggests that the first human groups arrived in the Santiago basin around the 10th millennium BC. These groups were primarily nomadic hunter-gatherers, traveling from the coast to the interior to hunt guanacos during the Andean snowmelt. By around 800 AD, the first permanent settlers established agricultural communities along the Mapocho River, where they cultivated crops such as maize, potatoes, and beans, and domesticated camelids.