Below are the countries you can enter without taking a Covid test prior to or on arrival, as long as you’re fully vaccinated. (Update: As of June 12, 2022, the U.S. no longer requires air travelers to show a negative test to enter the country.)
A growing number of countries have lifted all Covid requirements and don’t require either proof of vaccination or a negative test; you can find those here.
Additional countries welcome vaccinated travelers with a negative test or other requirements. You can find the full list of where you can travel here.
Ecuador and the Galapagos Islands
Africa and Middle East
United Arab Emirates
Asia and Pacific
Papua New Guinea