Chaleur Bay (baie des Chaleurs in French) is an arm of the Gulf of Saint Lawrence separating Quebec's Gaspé Peninsula from New Brunswick's "North Shore". The wide mouth of the Restigouche River is formed at the western-most (upper) end of the bay. The name was reportedly given by explorer Jacques Cartier. The French name means "bay of warmth" or "bay of torrid weather".

The name is misleading because the bay's water temperature is cold even in the middle of summer. This is not surprising, since the bay lacks the shallow depths of the nearby Northumberland Strait, which consequently has warmer water temperatures in summer months. Chaleur Bay has many fine beaches, set in pristine natural settings, and the sand can get very warm on the sunnier days of summer.

The following major rivers flow into the bay:

Quebec:

• Rivière Matapédia (via the Restigouche)
• Rivière Cascapédia
• Rivière Bonaventure
• Rivière du Grand Pabos

New Brunswick:

• Upsalquitch River (via the Restigouche)
• Nepisiguit River
• Tetagouche River
• Charlo River

Between both provinces:

• Restigouche River
• Patapedia River (via the Restigouche)

The is also a Chaleur Bay in Newfoundland and Labrador.