Čilić was eliminated in the second rounds of Indian Wells, Miami Open, and Madrid Open, but reached the quarterfinals in Rome, and Monte Carlo. In May, Čilić won the title at the Istanbul Open, defeating Milos Raonic in the final, in straight sets. This was his 14th ATP 250 title, second clay title, and 17th title overall. Additionally, Čilić's victory in Istanbul meant that 2017 was his tenth consecutive year winning at least one ATP title.
