UK, US, Canadian, South African and New Zealand passport holders do not require a visa for entry to Chile.
Australian Passport Holders - As of the 16th of December 2019 the administrative reciprocity fee of USD117, charged on arrival at Santiago airport, will be removed. Australian passport holders will not be required to pay this reciprocity fee to enter Chile.
Starting from 9th of May 2020 Australians passport holders will be required to obtain an e-visa in advance of entering Chile.
This e-visa can obtained on the Chilean government website. https://tramites.minrel.gov.cl/
If you are a passport holder of another nationality, check Project Visa for more information on visa requirements for Chile.