Face masks are no longer required for passengers flying to many EU destinations, but Germany, Greece, Italy and Spain are among countries keeping the mask rule.
The EU's easing from Monday is in line with changing Covid guidance on public transport across Europe.
France has lifted the face mask obligation on planes, trains and buses.
But Italy requires passengers to keep wearing the more protective FFP2 masks on public transport until 15 June.
In the 27-nation EU, the other countries that still require face masks on flights are: Portugal, Austria, Cyprus, Estonia, Lithuania, Malta, the Netherlands and Luxembourg.
The EU-wide easing was announced last week by the European Union Aviation Safety Agency (EASA), whose executive director Patrick Ky said "it is a relief to all of us that we are finally reaching a stage in the pandemic where we can start to relax the health safety measures".
EASA says vulnerable passengers should continue wearing FFP2 masks and passengers generally should try to observe social distancing where possible.
Face masks are no longer compulsory on flights to the UK and US.
The new guidance across the EU came with some cautionary advice from the European Centre for Disease Prevention and Control (ECDC).
ECDC director Andrea Ammon said that although the wearing of masks would no longer be compulsory, it was important to remember that "together with physical distancing and good hand hygiene, it is one of the best methods of reducing transmission".
"Further, as of 16 May 2022, aircraft operators, during their pre-flight communications as well as during the flight, should continue to encourage their passengers and crew members to wear face masks during the flight as well as in the airport, even when wearing a face mask is not required," the ECDC said.