There are twelve countries where the Euro Cup 2021 will be played. Each country has it's own requirements for entry.
Schengen Area Countries - Denmark,Germany, Hungary, Italy, Netherlands, Spain, . Romania follow Schengen Policy.
As a U.S. citizenship holder, you do not need to apply for a Schengen Visa! You are allowed to travel countries of the Schengen Area for up to 90 days for tourist or business purposes without a visa, as long as your U.S. passport is valid for at least 3 months after your planned return to the United States!
You must have a valid passport and an onward/return ticket for tourist/business "visa free" stays of up to 90 days. Your passports must be valid for the entire time you are staying in Japan. U.S. citizens cannot work on a 90-day "visa free" entry. As a general rule, "visa free" entry status may not be changed to another visa status without departing and then re-entering France with the appropriate visa, such as a spouse, work, or study visa.
You need a passport and a visa to enter Azerbaijan. Passport must be valid for at least 6 months after the expiration of the Azerbaijani visa. You will need to obtain your visa prior to travel. Visit the US State Department for additional information for Azerbaijan.
England & Scotland
No VISA is required to visit countries in the United Kingdom for tourist visits less than 90 day. Your USA passport must be valid for the duration of your stay. However; keep in mind other countries require 6 months as you plan which countries of the Euro Cup to visit. Visit the US State Department for additional information for the United Kingdom.
Republic of Ireland
Your USA passport must be valid for the duration of your stay in Ireland. No tourist visa is required. Visit the US State Department for additional information for Ireland.
A passport and Visa are required to enter Russia. Passport must be valid for 6 months beyond your stay. This has to be obtained prior to travel to Russia. Visit the US State Department for additional information for Russia.