The 2020 Western & Southern Open was a men's and women's tennis tournament being played on outdoor hard courts from August 22–29, 2020. It was the first Masters 1000 tournament on the 2020 ATP Tour and the second WTA Premier 5 tournament on the 2020 WTA Tour. This was the first ATP tournament since the Tour was suspended due to the COVID-19 pandemic.

The 2020 tournament was the 119th men's edition and the 92nd women's edition of the Cincinnati Open. This event normally took place in Cincinnati, Ohio, but was held at the USTA Billie Jean King National Tennis Center in New York City, United States, in order to reduce unnecessary player travel by centralizing the tournament and the subsequent US Open in the same venue.

¹ Rankings are as of March 16, 2020.

The following players received wild cards into the main singles draw:

The following player used a protected ranking into the main singles draw:

The following players received entry from the singles qualifying draw:

¹ Rankings are as of August 10, 2020

The following pairs received wildcards into the doubles main draw: