| Date: | September 10 – 16 |
| Edition: | 26th |
| Category: | WTA International |
| Draw: | 32S (24Q) / 16D (0Q) |
| Surface: | Carpet – indoors |
| Location: | Quebec City, Canada |
| Venue: | PEPS de l'Université Laval |
| Champs: |  Pauline Parmentier |
| Champd: |  Asia Muhammad / Maria Sanchez |
| Main Name: | Tournoi de Québec |
The 2018 Coupe Banque Nationale is a tennis tournament played on indoor carpet courts. It was the 26th edition of the Tournoi de Québec and part of the WTA International tournaments of the 2018 WTA Tour. It took place at the PEPS de l'Université Laval in Quebec City, Canada, from September 10 through September 16, 2018.
| Event | W | F | SF | QF | Round of 16 | Round of 32 | Q | Q2 | Q1 |
| Singles | 280 | 180 | 110 | 60 | 30 | 1 | 18 | 12 | 1 |
|---|---|---|---|---|---|---|---|---|---|
| Doubles | 1 |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | Q2 | Q1 | |
| Singles | $43,000 | $21,400 | $11,500 | $6,175 | $3,400 | $2,100 | $1,020 | $600 | |
| Doubles | $12,300 | $6,400 | $3,435 | $1,820 | $960 |
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Belarus | Aryna Sabalenka | 20 | 1 | |
| Petra Martić | 47 | 2 | ||
| Monica Puig | 55 | 3 | ||
 Romania | Monica Niculescu | 62 | 4 | |
| United States | Sofia Kenin | 65 | 5 | |
 Czech Republic | Lucie Šafářová | 69 | 6 | |
| Tatjana Maria | 70 | 7 | ||
| France | Pauline Parmentier | 71 | 8 |
The following players received wildcards into the singles main draw:
The following player entered the singles main draw with a protected ranking:
The following players received entry from the qualifying draw:
Anna Blinkova → replaced by Veronika Kudermetova Danielle Collins → replaced by 
Naomi Broady
Olga Danilović → replaced by 
Ons Jabeur Vitalia Diatchenko → replaced by Madison Brengle Margarita Gasparyan → replaced by 
Beatriz Haddad Maia Anastasia Pavlyuchenkova → replaced by Heather Watson
Peng Shuai → replaced by Mona Barthel Sachia Vickery → replaced by Georgina García Pérez| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
| United States | Kaitlyn Christian | United States | Sabrina Santamaria | 108 | 1 | |
| Darija Jurak | Xenia Knoll | 137 | 2 | |||
| United States | Desirae Krawczyk |  Mexico | Giuliana Olmos | 151 | 3 | |
| Russian Federation | Natela Dzalamidze | Russian Federation | Veronika Kudermetova | 183 | 4 |
The following pairs received wildcards into the doubles main draw:
See main article: 2018 Coupe Banque Nationale – Singles.
Pauline Parmentier def. Jessica Pegula 7–5, 6–2See main article: 2018 Coupe Banque Nationale – Doubles.
Asia Muhammad / Maria Sanchez def. Darija Jurak / Xenia Knoll 6–4, 6–3