The Czech Republic (Czechia) is a member of the European Union (EU) and the Schengen area, therefore most tourist visitors do not require a visa to visit Prague, just a valid passport (or ID card for EU citizens).
Visas ARE NOT required for stays up to 90 days by citizens of many countries.
For additional information regarding entry requirements into the Czech Republic, please contact the nearest embassy or consulate, or you may visit the Ministry of Foreign Affairs of the Czech Republic’s website, at: