Route 145 is a state highway in the western part of the Connecticut River Estuary region of Connecticut. It connects Clinton center, through the village of Winthrop, to the town of Chester.

Route 145 begins at an intersection with US 1 in Clinton and heads northeast, into Westbrook. In Westbrook, it turns north, intersecting with I-95 and passing by the Messerschmidt Pond Wildlife Area, before continuing into the town of Deep River. In Deep River, it continues north through the Winthrop section of the town, briefly overlapping Route 80 before continuing into Chester. In Chester, it continues north and northeast, curving around Chester Airport before ending at an intersection with Route 148 within the Cockaponset State Forest.

Route 145 was established in 1932, following a loop around the Clinton Country Club and passing by the beach communities of Grove Beach and Clinton Beach within the town of Clinton. In 1959, it was extended as a tail north through Westbrook to the former Route 144 (now a town road called Bushy Hill Road) in Deep River. In 1942 or 1943, its northern end was relocated and extended northward to Route 80. In 1962, it was extended to its current northern terminus at Route 148 and the portion south of US 1 became town roads. Part of old Route 145 called Grove Beach Road between current Route 145 and US 1 is still a state road with unsigned designation State Road 625.

The entire route is in Middlesex County.

Location	mi	km	Destinations	Notes
Clinton	0.00	0.00	US 1 – Westbrook, Madison
Westbrook	1.37	2.20	SSR 625 (Grove Beach Road North)
	1.98	3.19	I-95 / Conn. Turnpike – New London, New Haven	Exit 64 on I-95/Conn. Tpk.
Deep River	6.64	10.69	Route 80 west – Killingworth	Western terminus of CT 80 overlap
	6.99	11.25	Route 80 east – Deep River	Eastern terminus of CT 80 overlap
Chester	9.91	15.95	Route 148 – Hadlyme, Killingworth
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus