Despite boasting record passenger numbers, the low-cost carrier made a pre-tax loss of £236m in the six months to the end of March compared to a £18m loss in the same period last year.
Headline losses also deepened by £191m to £212m.
Total revenue grew 3.2% to £1.827bn and as the airline flew a record 33.8 million passengers in the six months - up 9% from a year before.
Revenues over the period rose slightly by 3.2% while load factor also rose by 0.5 percentage points to 90.2%.
EasyJet announced it would be launching its largest pilot recruitment drive in June, as it looks for an additional 450 pilots.
Despite its financial shortfall the carrier said its performance had been "resilient" and the losses were in line with market expectations.
Carolyn McCall, chief executive, said easyJet’s loss “reflects the movement of Easter into the second half as well as currency effects which together had an estimated impact of circa £127m on the bottom line”.
“Looking ahead, we are seeing an improving revenue per seat trend as well as the continued reduction of competitor capacity growth. Cost performance for the full year will continue to be strong. EasyJet is delivering on its strategy of purposeful investment in securing and building strong positions at Europe’s leading airports which is driving competitive advantage with sustainable returns.
"Our bookings for the summer are ahead of last year showing that demand to fly remains strong and reflects growing evidence that consumers are prioritising expenditure on flights and holidays above other non-essential items.
“As a result our expectations for the full year are in line with current consensus market expectations,” McCall added.