Three attackers were involved, with one reportedly firing a Kalashnikov as they targeted the main entry point to Ataturk international airport.
The attackers blew themselves up after police fired at them, officials have confirmed.
Majority of the casualties were Turkish.
Recent bombings in Turkey have been linked to either secular Kurdish separatists or ISIS.
Turkish President Recep Tayyip Erdogan condemned the attack, calling for a “joint fight” against terrorism, as he confirmed that the perpetrators were linked to ISIS.
The US condemned the “heinous” attack, saying America remained “steadfast in our support for Turkey”.
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German Foreign Minister Frank-Walter Steinmeier said: “We grieve for the victims… We stand by Turkey”.
Flights in and out of the airport were suspended after the attack.
The US Federal Aviation Administration grounded all flights between the US and Istanbul, Reuters reports.
Taxis were used to rush casualties to hospital after the attack.
Security concerns and a Russian boycott over last year’s downing of a Russian military jet on the Turkey-Syria border have hit the Turkish tourist sector this year.
More than 61 million passengers travelled through Ataturk airport in 2015.
