Sterna hirundo, commonly known as the Common Tern, has a widespread geographical distribution. It is found across North America, Europe, and Asia during the breeding season. In North America, its range extends from central Canada to the northeastern and central United States. In Europe, it is found across many countries, from the British Isles and Scandinavia to the Mediterranean and Black Sea regions. In Asia, it breeds in regions extending from western Siberia to Mongolia.

The Common Tern typically inhabits coastal and inland water bodies. It prefers sandy or pebbly beaches, riverbanks, and islands while breeding, often in colonies. The climate in these regions can vary greatly, from temperate zones in Europe and North America to more extreme temperatures in Siberia and Mongolia.

Sterna hirundo occupies an ecological niche as a piscivorous bird, primarily feeding on small fish but also consuming insects and crustaceans. It has adapted to a variety of coastal and freshwater environments, utilizing its agile flight and diving capabilities to forage efficiently. In terms of breeding, they often select locations protected from terrestrial predators and human disturbance, indicating a preference for remote or protected habitats, including conservation reserves and uninhabited islands.