The Hartford Dark Blues were a 19th century baseball team. The team was based in Hartford, Connecticut. They were a member of the National Association of Professional Baseball Players in 1874 and 1875.

In 1876 they joined the National League as a charter member.

The team left Hartford and moved to Brooklyn, New York for the 1877 season to become the Brooklyn Hartfords. The team disbanded after the 1877 season.