Colona is a city in Henry County, Illinois, along the Green River. It is part of the Quad Cities metropolitan area. The population was 5,099 at the 2010 census, down from 5,173 at the 2000 census.
The City of Colona was created in 1997 by the merger of the former City of Green Rock and the former Village of Colona. It was the first community in Illinois to merge by popular vote.
Colona is located at 41°28′32″N 90°20′56″W (41.475684, -90.348787). Colona lies near the Rock River in a valley, and is surrounded by higher land. This is where the Green River and Hennepin Canal flow into the Rock River (Mississippi River).
According to the 2010 census, Colona has a total area of 4.126 square miles (10.69 km2), of which 4.02 square miles (10.41 km2) (or 97.43%) is land and 0.106 square miles (0.27 km2) (or 2.57%) is water.
As of the census of 2000, there were 5,173 people, 1,936 households, and 1,473 families living in the city. The population density was 1,479.1 people per square mile (570.7/km2). There were 2,010 housing units at an average density of 574.7 per square mile (221.7/km2).