Suwanee is a city in the American state of Georgia. It is in Gwinnett County. In 2005, about 12,500 people lived in Suwanee. According to the United States Census Bureau, the city has a total area of 25.6 km² (9.9 mi²). 25.4 km² (9.8 mi²) of it is land and 0.2 km² (0.1 mi²) of it (0.71%) is water.