Gatwick will see airline capacity rise to the equivalent of 16.9 million departing seats this summer with the addition of ten new routes.
Long-haul destinations are among the fastest-growing including Doha and Buenos Aires.
Carriers are also raising frequency to a number of European destinations.
These include Almeria, Bilbao, Jerez, Alicante, Antalya, Kos and Budapest.
Airlines are also increasing routes to the more untapped parts of Europe, including Ancona in Italy and Volos and Kavala in Greece.
New routes include Asturias in Spain, Chisinau, Moldova; Cluj Napoca in Romania, Gdansk, Poland; Lametia-Terme, Italy; Miami; Rijeka in Croatia; Rio de Janeiro, San Francisco and Zadar, Croatia.
The summer forecast came as Gatwick predicted a 5.1% rise in Easter weekend passengers to 550,000 over last year.
Head of airline relationsStephen King said:“This summer, ten new routes will start, which is the very latest demonstration of passenger demand for flights from Gatwick.
“It shows that, even though it’s one of the busiest in Europe, airlines can still acquire slots and grow at our airport.
“Rio de Janeiro has just joined Gatwick’s roster of long-haul connections while our airlines are opening up new must-see destinations to explore, particularly in Europe.
“Our summer seat availability is nearly double that of our winter season.”