[6] The breeding habitat is near lakes, rivers, or the coast across most of Canada, and the northern United States.
The ring-billed gull is a familiar sight in North American parking lots, where it can regularly be found congregating in large numbers.
In Ireland and Great Britain it is no longer classed as a rarity, with multiple birds regularly wintering in those countries, though has become rarer again since about 2010.
[11] Ring-billed gulls forage in flight or pick up objects while swimming, walking or wading.
They are omnivorous; their diet may include insects, fish, grain, eggs, earthworms and rodents.
It is regarded as a pest by many beach-goers because of its willingness to steal unguarded food on crowded beaches.