Route 209 is a rural state highway in northwestern Connecticut, running from the Lakeside part of Morris to the borough of Bantam in the town of Litchfield.

It heads north along the west shore of Bantam Lake for 1.9 miles (3.1 km) into the town of Litchfield.

Route 209 is known as Bantam Lake Road for its entire length.

[1] The road connecting the town of Morris with the borough of Bantam going alongside Bantam Lake was designated as a secondary state highway known as Highway 310 in 1922.

In 1963, Route 109 was reconfigured such that it went west toward Washington instead.