The third major airport to serve the Istanbul area will be based on the European side of the city near to the Black Sea coast, Turkish media reports suggest.
Transport minister Binali Yildirim says that the airport will have six runways and an annual capacity of 120 million passengers.
The city's main airport, Ataturk International, already operates close to its full capacity of 38 million passengers, Yildirim notes. With second airport Sabiha Gokcen now also surpassing the 12 million passenger mark, he says there is an "urgent" need for a third hub.
Based 30km (18.6 miles) northwest of Ataturk Airport, the new base will have a total area of 35km². Operations will be ramped up at the airport across three phrases, with the first phase due for completion in 2016.
Yildirim says the new airport will be "one the biggest in the world", adding: "With 120 million passenger capacity, our aim is to serve Istanbul's growing capacity until 2050."
A tender for the construction of the new base will be held in September.