- Southern Terminus:
- South Main Street (CT 63) in Naugatuck
- Northern Terminus:
- Ansonia-Derby Expressway (CT 8) in Naugatuck
- 0.27 miles
- New Haven
SR 709 is the designation for the portion of South Main Street in Naugatuck north of the point where CT 63 turns off of it to cross the Naugatuck River. It carries traffic between CT 63 and the Ansonia-Derby Expressway (CT 8). It is a two-lane undivided road and is only a few blocks long.