The 2018 Istanbul Open (also known as the TEB BNP Paribas Istanbul Open for sponsorship purposes) was a men's tennis tournament played on outdoor clay courts.

[1] It was the fourth edition of the Istanbul Open, and an ATP World Tour 250 event.

It took place at the Koza World of Sports Arena in Istanbul, Turkey, from 30 April–6 May 2018.

[2] The following players received wildcards into the main draw: The following players received entry from the qualifying draw: The following pairs received wildcards into the doubles main draw: