Guilford is a town in New Haven County, Connecticut, United States, that borders Madison, Branford, North Branford and Durham, and is situated on I-95 and the coast. The population was 22,375 at the 2010 census. In 2015 the population stands at approximately 22,413 people. It was named one of the top 100 places to live in the United States by Money magazine in 2005.