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.[1]
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Dominic Thiem | 8 | 1 | ||
| Fabio Fognini | 13 | 2 | ||
| Marco Cecchinato | 22 | 3 | ||
| Karen Khachanov | 25 | 4 | ||
| Roberto Bautista Agut | 26 | 5 | ||
| Damir Džumhur | 28 | 6 | ||
| Denis Shapovalov | 34 | 7 | ||
| Daniil Medvedev | 35 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
Marcos Baghdatis → replaced by 
Ruben Bemelmans
Jozef Kovalík → replaced by Marcos Baghdatis
Leonardo Mayer → replaced by 
Evgeny Donskoy| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
 United Kingdom | Dominic Inglot | Franko Škugor | 62 | 1 | ||
| Julio Peralta | Argentina | Horacio Zeballos | 65 | 2 | ||
 Czech Republic | Roman Jebavý | Matwé Middelkoop | 80 | 3 | ||
 Sweden | Robert Lindstedt | Rajeev Ram | 98 | 4 |
The following pairs received wildcards into the doubles main draw:
See main article: 2018 St. Petersburg Open – Singles.
Dominic Thiem def. Martin Kližan, 6–3, 6–1See main article: 2018 St. Petersburg Open – Doubles.
Matteo Berrettini / Fabio Fognini def. Roman Jebavý / Matwé Middelkoop, 7–6(8–6), 7–6(7–4)
