High Quality Content by WIKIPEDIA articles! Alpharetta is a city in north Fulton County, Georgia, United States and a northern suburb of Atlanta, Georgia. It is one of the most affluent communities in the state. According to the 2010 Census, Alpharetta`s population is 57,551. However, during the workday, the city swells to more than 120,000 residents, workers, and visitors, due to the more than 3,600 businesses that are located in the city.