Bloc Hotels is looking to nearly double the size of its 245-bedroom property at the South Terminal of Gatwick Airport.
The company has applied for planning permission to add 231 new sound-proofed bedrooms within a new aluminium and glass wing, linked to the existing hotel by a passenger bridge.
Since opening at the airport in 2014, Bloc had operated at more than 90% occupancy.
Rob Morgan, managing director at Bloc Hotel Group, said: "Gatwick Airport has been home to Bloc Hotels for five years and we are delighted to be part of the fabric of this fabulous travel hub. There is unprecedented demand from passengers wanting to stay with us."
Emma Rees, head of property, Gatwick Airport, added: "Bloc's entrance sits just a few metres from South Terminal's Departures, so extending the hotel will provide even more of our passengers with super-fast, convenient access to our terminals.
"The hotel is a fantastic option for travellers with an early flight and many of the new rooms will also offer guests spectacular views of the busiest single runway in the world."
If given the go ahead, the Bloc Gatwick extension is expected to open in 2021.
Alongside its Gatwick hotel, Block operates a 105-bedroom hotel in Birmingham. It is building a second hotel in Birmingham with 227 bedrooms and has just acquired a site in Glasgow to develop a hotel with retail space.