2013 Western & Southern Open – Men's singles

Rafael Nadal defeated John Isner in the final, 7–6, 7–6 to win the men's singles tennis title at the 2013 Cincinnati Open. It was his record-extending 26th Masters title. Nadal was the second man (after Novak Djokovic) to win four consecutive Masters 1000 events.

Roger Federer was the defending champion, but lost in the quarterfinals to Nadal.