According to data released by the Turkish Statistics Institute on Tuesday, tourism revenue in 2016 amounted to $22.1 billion - a drop of 29.7 percent from 2015.
The decline comes amid a wave of deadly attacks in the country, including one on Istanbul's main airport at the height of the tourist season in June, which killed more than 40 people, the Associated Press reported.
Foreign visitors have also been deterred by a failed coup attempt in July that led to a state of emergency and a massive government crackdown on people suspected of links to the coup and other opponents.