General Discussion

https://travel.state.gov/content/travel/en/us-visas/visa-information-resources/fees/fees-visa-services.html

Visa Waiver Program

https://travel.state.gov/content/travel/en/us-visas/tourism-visit/visa-waiver-program.html

Citizens of Canada and Bermuda

https://en.wikipedia.org/wiki/Visa_policy_of_the_United_States

Citizens of freely associated states

Marshall Islands
Micronesia
Palau

Under Compacts of Free Association, citizens of the Marshall Islands, Micronesia and Palau may enter, reside, study and work in the United States indefinitely without a visa. These benefits are granted to citizens from birth or independence, and to naturalized citizens who have resided in the respective country for at least five years, excluding those who acquired citizenship by investment.

Nationals of neighboring jurisdictions

The United States grants visa-free entry to nationals of two neighboring jurisdictions under most circumstances:

Bahamas – Nationals of the Bahamas do not need a visa to the United States if they apply for admission at a U.S. preclearance facility located in the Bahamas. In addition to a Bahamian passport, applicants 14 years of age or older must present a police certificate issued by the Royal Bahamas Police Force in the previous six months indicating no criminal record.

British Virgin Islands – British Overseas Territories citizens of the British Virgin Islands may travel without a visa to the U.S. Virgin Islands with their British Virgin Islands passport. They may also continue travel to other parts of the United States if they present a Certificate of Good Conduct issued by the Royal Virgin Islands Police Force indicating no criminal record.

Cayman Islands – British Overseas Territories citizens of the Cayman Islands may travel without a visa to the United States. To qualify, they must receive a visa waiver from the Cayman Islands Passport and Corporate Services Office, for which they must present a Cayman Islands passport valid for at least six months beyond their intended departure from the United States, a fee of 25 Cayman Islands dollars, and a police clearance certificate for applicants age 13 or older. The visa waiver is valid for only one entry and for travel directly from the Cayman Islands to the United States.

Turks and Caicos Islands – British Overseas Territories citizens of the Turks and Caicos Islands may travel to the United States without a visa for short stays for business or pleasure. To qualify, they must travel directly from the territory to the United States, present a Turks and Caicos Islands passport or another travel document stating that they are British Overseas Territory citizens with the right of abode in the Turks and Caicos Islands, and applicants 14 years of age or older must also present a police certificate issued by the Royal Turks and Caicos Islands Police Force in the previous six months indicating no criminal record.

Visa-free entry is also granted to limited categories of nationals of another neighboring country:

Mexico – Some nationals of Mexico do not need a visa to travel to the United States: government officials not permanently assigned to the United States and their accompanying family members, holding diplomatic or official passports, for stays of up to 6 months; members of the Kickapoo tribes of Texas or Oklahoma, holding Form I-872, American Indian Card; and crew members of Mexican airlines operating in the United States. Other nationals of Mexico may travel to the United States with a Border Crossing Card, which functions as a visa and has similar requirements. Under the USMCA (and earlier NAFTA), they may also obtain authorization to work under a simplified procedure.

Visa exemption