Renton is a city in King County, Washington, United States. It is 13 miles (21 km) southeast of Seattle, Washington. Renton is on the southeast shore of Lake Washington. At the 2000 census, 50,052 people lived there. As of April 1, 2008, there were about 78,780 people. The number of people increased a lot because of the addition of the Benson Hill communities directly southeast of the city. According to the data from the Office of Financial Management, Renton is the 11th largest city in Washington, and 5th largest in King County.