Vueling is to operate 278 international routes in summer 2023, 23 of them from British airports.
Describing itself as "the largest airline outside Britain connecting the United Kingdom with Spain", Vueling said it was also "the second main operator between London-Gatwick and Spain".
The International Airlines Group carrier said 17 of its UK connections are to be from London-Gatwick, with the remainder split between Birmingham, Cardiff, Edinburgh and Manchester.
"We continue reinforcing our position in Spain with outstanding leadership in Barcelona and Bilbao, in addition to consolidating our international commitment through London-Gatwick and Paris-Orly," said Carolyn Prowse, the airline's chief commercial, customer, strategy and network officer.
Forecasting 9% annual growth, the airline said it would "maintain 2019 operation levels this summer".