The largest agglomerations according to the 2002 census are Greater Santiago with 5.6 million people, Greater Concepción with 861,000 and Greater Valparaíso with 824,000.

Chile is a multiethnic society, home to people of many different ethnic backgrounds. Studies on the ethnic structure of Chile vary significantly from one another.

An autosomal DNA study from 2014 found out Chile to be 44.34% (± 3.9%) native American, 51.85% (± 5.44%) European and 3.81% (± 0.45%) African.A 2015 study analyzing hundreds of thousands of SNPs yielded similar results — around 55% European, 43% Native, and 2% African.

A public health book from the University of Chile states that 30% of the population is of Caucasian origin; Mestizos with an average 60% Caucasian ancestry and 40% Native American ancestry are estimated to amount a total of 65%, while Native Americans (Amerindians) comprise the remaining 5%. A genetic study by the same university showed that the average Chilean's genes are 64% Caucasian and 35% Amerindian.

UNAM professor of Latin American studies, Francisco Lizcano, in his social research estimates that a predominant 52.7% of the Chilean population can be classified as culturally European, with an estimated 44% as Mestizo.Other social studies put the total amount of Whites at over 60 percent.

 Some publications, such as the CIA World Factbook, state that the entire population consist of a combined 95.4% of "Whites and White-Amerindians", and 4.6% of Amerindians. These figures are based on a national census held in 2002, which classified the population as indigenous and non-indigenous, rather than as White or Mestizo.

Despite the genetic considerations, many Chileans, if asked, would self-identify as white. The 2011 Latinobarómetro survey asked respondents in Chile what race they considered themselves to belong to. Most answered "white" (59%), while 25% said "mestizo" and 8% self-classified as "indigenous".

 A 2002 national poll revealed that a majority of Chileans believed they possessed some (43.4%) or much (8.3%) "indigenous blood", while 40.3% responded that they had none.

The Spanish spoken in Chile is distinctively accented and quite unlike that of neighbouring South American countries because final syllables and "s" sounds are dropped, and some consonants have a soft pronunciation. Accent varies only very slightly from north to south; more noticeable are the small differences in accent based on social class or whether one lives in the city or the country. 

That the Chilean population was largely formed in a small section at the center of the country and then migrated in modest numbers to the north and south helps explain this relative lack of differentiation, which was maintained by the national reach of radio, and now television, which also helps to diffuse and homogenize colloquial expressions.

There are several indigenous languages spoken in Chile: Mapudungun, Quechua, Aymara and Rapa Nui. After the Spanish invasion, Spanish took over as the lingua franca and the indigenous languages have become minority languages, with some now extinct or close to extinction.

German is spoken to a great extent in southern Chile, either in small countryside pockets or as a second language among the communities of larger cities.

Through initiatives such as the English Opens Doors program, the government made English mandatory for students in fifth-grade and above in public schools. Most private schools in Chile start teaching English from kindergarten.Common English words have been absorbed and appropriated into everyday Spanish speech.

 Since 2010, all students from 3rd grade in secondary school have been tested on listening and reading comprehension for English language. The evaluation is compulsory and the instrument is TOIEC Bridge, developed by Educational Testing Service.