The first flight to Sabiha Gokcen airport took off on Monday morning (1 July).
However, from 21 July, Pegasus will increase frequency to daily flights.
The airline said the route would complement its existing four-times daily service from Stansted.
Flights will depart Manchester at 12.40pm, arriving Istanbul 6.50pm.
Return flights will depart Istanbul at 9.30am, arriving Manchester at 11.55am.
Fares lead in from £79.99pp one way.
Pegasus offers onward connections to 32 destinations across Turkey and a further 39 international destinations.
