2018 St. Petersburg Open

The 2018 St. Petersburg Open was a tennis tournament played on indoor hard courts. It was the 23rd edition of the St. Petersburg Open, and part of the ATP World Tour 250 Series of the 2018 ATP World Tour. It took place at the Sibur Arena in Saint Petersburg, Russia, from September 17 through 23, 2018.

Seeds

 * 1 Rankings are as of September 10, 2018

Other entrants
The following players received wildcards into the singles main draw:
 * 🇪🇸 Roberto Bautista Agut
 * Stan Wawrinka
 * 🇷🇺 Mikhail Youzhny

The following players received entry from the qualifying draw:
 * 🇧🇾 Ilya Ivashka
 * 🇪🇸 Adrián Menéndez Maceiras
 * 🇦🇹 Lucas Miedler
 * 🇮🇹 Luca Vanni

The following player received entry as a lucky loser:
 * 🇧🇪 Ruben Bemelmans

Withdrawals

 * Before the tournament
 * 🇨🇾 Marcos Baghdatis → replaced by 🇧🇪 Ruben Bemelmans
 * 🇸🇰 Jozef Kovalík → replaced by 🇨🇾 Marcos Baghdatis
 * 🇦🇷 Leonardo Mayer → replaced by 🇷🇺 Evgeny Donskoy

Seeds

 * Rankings are as of September 10, 2018

Other entrants
The following pairs received wildcards into the doubles main draw:
 * 🇷🇺 Mikhail Elgin / 🇺🇿 Denis Istomin
 * 🇷🇺 Teymuraz Gabashvili / 🇷🇺 Evgeny Karlovskiy

Withdrawals

 * During the tournament
 * 🇺🇿 Denis Istomin

Singles

 * 🇦🇹 Dominic Thiem def. 🇸🇰 Martin Kližan, 6–3, 6–1

Doubles

 * 🇮🇹 Matteo Berrettini / 🇮🇹 Fabio Fognini def. 🇨🇿 Roman Jebavý / Matwé Middelkoop, 7–6(8–6), 7–6(7–4)