All Wizz Air flights from the UK to Romania were suspended from (Monday).
The low cost carrier has had to respond to travel restrictions introduced by the Romanian government to contain the spread of Covid-19.
The airline has been running a reduced number of three weekly flights to the Romanian capital of Bucharest from Southend airport.
Repatriation flights to and from Romania were also being operated from Birmingham, Doncaster/Sheffield, Edinburgh, Gatwick, Liverpool and Luton airports.
Passengers who booked direct will be refunded 120% of the original fare as airline credit, which can be used in the next two years. Alternatively, they can opt for a 100% refund.
Those who made their bookings via travel agencies are being told by the airline to get in touch with the company they purchased their tickets from.
The carrier said: “Wizz Air sincerely apologises for any inconvenience caused by these cancellations, and thanks loyal customers for their patience during these challenging times.
“As ever, the safety and well-being of passengers and crew remains the airline’s top priority.”