2017 Challenger Banque Nationale de Gatineau – Men's singles

Peter Polansky was the defending champion but lost in the final to Denis Shapovalov.

Shapovalov won the title after defeating Polansky 6–1, 3–6, 6–3 in the final.

Seeds
• # 🇹🇳 Malek Jaziri (semifinals)

• # 🇮🇹 Thomas Fabbiano (quarterfinals)

• # Blaž Kavčič (second round, retired)

• # 🇯🇵 Go Soeda (second round)

• # 🇨🇦 Peter Polansky (final)

• # Jason Jung (first round)

• # 🇨🇦 Denis Shapovalov (champion)

• # 🇫🇷 Vincent Millot (quarterfinals)