The barn swallow is the most common and widespread of all swallow species. It is found in Europe, Africa, Asia and the Americas. They choose to live almost exclusively in man-made structures, as their name suggests. Although fast and agile, swallows have several prominent predators and many less threatening predators.

Hawks, falcons and kestrels are the primary predators of adult swallows. Cooper’s hawk and peregrine falcons are the best examples of a barn swallow's biggest predators. Adapted well for catching other flying birds, these two species are fast, agile and powerful hunters. Kestrels may also kill swallows if easier prey is scarce.

Due to the fact that owls mostly hunt at night, they are not as much of a threat to swallows as other birds of prey. They do, however, hunt in the early mornings or evenings when swallows may be around. Gulls are not picky and have a wide range of food sources, as they will either scavenge for scraps or when possible catch their own prey. Due to their size, they can dominate smaller animals and birds such as the swallow, though because of their slow, clumsy nature, this is a rarity.

Rats, squirrels, raccoons, bobcats and domestic cats will all feed on swallows. As adult swallows feed in mid-air, they rarely spend time on the ground, making them unlikely prey for this range of animals. Instead these predators are more likely to raid the swallow nest and eat the eggs or young chicks. Swallow nests are high in the roof areas of buildings, making them as isolated as possible from such potential threats.

Snakes, bullfrogs, fish and fire ants are some of the least likely predators of the barn swallow. In exceptional circumstances, all of these creatures have been known to kill and eat either adult swallows or (with the exception of fish and bullfrogs) raid the nest for eggs and chicks. Snakes and bullfrogs are large enough to eat an adult swallow. However, their means of catching prey does not correlate with the way swallows live, making it extremely rare.