Robusta is a sturdy species of coffee bean with low acidity and high bitterness; it is used primarily in instant coffee, espresso, and as a filler in ground coffee blends. The bean comes from the Coffea robusta variety of the Coffea canephora plant (widely known itself by the synonym Coffea robusta) which has its origins in central and western sub-Saharan Africa. Robusta is easy to care for, has a greater crop yield than arabica coffea, has almost double the amount of caffeine and more antioxidants than arabica coffea, and is less susceptible to disease. Roasted robusta beans produce a strong, full-bodied coffee with a distinctive earthy flavour, but usually with more bitterness than arabica due to its pyrazine content.

Approximately 30% of the coffee produced in the world is robusta. It is mostly grown in Vietnam, where French colonists introduced it in the late 19th century, though it is also grown in Africa and Brazil, where it is often called conilon. In recent years, Vietnam, which produces mostly robusta, has surpassed Brazil, India, and Indonesia to become the world's single largest exporter of robusta coffee. Brazil is still the biggest producer of coffee in the world, producing one-third of the world's coffee, though 80% of that is C. arabica.

Robusta is easier to care for and has a greater crop yield than C. arabica, so is cheaper to produce. Roasted robusta beans produce a strong, full-bodied coffee with a distinctive earthy flavour, but usually with more bitterness than arabica due to its pyrazine content. Since arabica beans are believed to have smoother taste with less acidity and a richer flavour, they are often considered superior, while the harsher robusta beans are mostly used as a filler in lower-grade coffee blends. However, the powerful flavour can be desirable in a blend to give it perceived "strength" and "finish", noticeably in Italian coffee culture. Good-quality robusta beans are used in traditional Italian espresso blends, at about 10-15%, to provide a full-bodied taste and a better foam head (known as crema). It is besides used as a stimulant, diuretic, antioxidant, antipyretic and relieves spasmodic asthma.