The 259-room Hotel Sisli is situated within a 34-storey building on the European side of Istanbul, between the business districts of Levent and Taksim.
The property has 1,300 square metres of event space and showcases Marriott's new meetings technology, Red Coat Direct digital concierge, which allows planners to edit meeting requests at the touch of a button, and Meetings Imagined, a new digital platform with inspiring ideas, top tips and case studies.
Amy McPherson, president and managing director for Marriott International in Europe, said: "We are delighted to open this magnificent hotel in Istanbul and build on our strong portfolio in Turkey.
"Everything from technology and design to meetings is being revitalised and we are very proud that the Istanbul Marriott Hotel Sisli showcases many of these innovations."
Hotel Sisli also offers a health club and spa, gym, indoor swimming pool, tennis court, Turkish bath, sauna, steam room, treatment rooms and, for VIPs, a rooftop helipad.