Chile's 2017 census reported a population of 17,574,003 people. Its rate of population growth has been decreasing since 1990, due to a declining birth rate. By 2050 the population is expected to reach approximately 20.2 million people, at which point it is projected to either stagnate or begin declining. About 85% of the country's population lives in urban areas, with 40% living in Greater Santiago alone. 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.

Chileans are an ethnic group and nation native to the country of Chile and its neighboring insular territories. Most Chileans share a common culture, history, ancestry and language. The overwhelming majority of Chileans are the product of varying degrees of admixture between European ethnic groups with peoples indigenous to Chile's modern territory. Chile is a multilingual and multicultural society, but an overwhelming majority of Chileans have Spanish as their first language and either are Christians or have a Christian cultural background.