The 2016 St. Petersburg Open was a tennis tournament played on indoor hard courts.

It was the 21st edition of the St. Petersburg Open, and part of the ATP World Tour 250 Series of the 2016 ATP World Tour.

It took place at the Sibur Arena in Saint Petersburg, Russia, from 19 September through 25 September 2016.

Fifth-seeded Alexander Zverev won the singles title.

The following players received wildcards into the singles main draw: The following player received entry using a protected ranking: The following players received entry from the qualifying draw: The following pairs received wildcards into the doubles main draw: