The airport is competing with Heathrow to expand, with a decision due to be made by the government later this year.
Gatwick's pre-tax profits jumped 77% to £141m in the year to March.
The results were published as the government announced a deferral on a decision on airport expansion until the new Conservative leader is elected.
Stewart Wingate, Gatwick's chief executive, said turnover was up 5.5% to £673.1m after the busiest year in the airport's history.
He said the results demonstrated the support and momentum behind Gatwick as the site for expansion.
"It has become ever more clear that only Gatwick can deliver a new runway for Britain and the growth the economy needs," Mr Wingate said.
Gatwick said 2.1m more passengers had passed through its terminals in the past 12 months - bringing the total to 40.8m, with many taking advantage of its 50 long-haul routes.
Mr Wingate said: "Aviation is changing fast and Gatwick has now entered the premier league of airports.
"In uncertain times and after decades of delay, only Gatwick can now give Britain certainty that airport expansion can finally happen.
"Gatwick can have a spade in the ground by 2020 and the first planes flying from a new runway in 2025."
But campaigners who have already spent years fighting a second runway in West Sussex are upbeat in the face of further uncertainty.
"Here's an opportunity for the new parliament, the new government, new leader, to look at it and [give] a much better assessment of what's needed," said Peter Barclay, of the Gatwick Area Conservation Campaign.
Crawley Borough Councillor Brian Quinn (Labour) disagreed:  "I know there's opposition in the town, like 50/50, but we've got to think of the future and the youngsters as well."
Heathrow bosses have said extending its runway capacity was key.
"If Britain wants to be confident, outward-looking and at the centre of the world's economy, then expanding Heathrow must be a key building block in the government's Brexit plan," a spokesman said.
"It will allow British exporters to trade with all the growing markets of the world.  And, at a time of uncertainty, a £16bn privately-funded infrastructure investment will create jobs and growth across the UK."
The west London airport was favourite to be picked as the site for a new runway, but Prime Minister David Cameron has since announced his resignation and Boris Johnson, leadership contender, had promised to lie down in front of bulldozers to stop expansion there.
On Thursday, Mr Johnson said he would not run for the leadership of the party.
Gatwick's results were published a year after the Airports Commission gave its recommendations, which backed a third Heathrow runway but said Gatwick expansion was still credible.
Heathrow said more than 170 of Britain's business leaders had written to the Transport Secretary on the anniversary to urge the government to inject growth into the economy by progressing with the Heathrow expansion option.
Gatwick released an anniversary document, which said one year on from the debate it was clear only Gatwick could deliver the runway.
Gatwick Airport has called for a swift decision on airport expansion in south-east England after it published its annual results.