Route 33 is a 14.41-mile (23.19 km), secondary north–south state highway in the U.S. state of Connecticut, from Westport to Ridgefield.

Route 33 begins at an intersection with Route 136 and I-95 in Westport. It heads north, intersecting with US 1, Route 57, and Merritt Parkway (Route 15) before crossing into Norwalk. Route 33 barely crosses the northeastern corner of Norwalk before continuing into Wilton. Where it passes through the Wilton Center Historic District.

In Wilton, Route 33 heads northwest, crossing Route 53 before joining US 7 and Route 106, in that order, to form a triple concurrency. Route 106 leaves the concurrency shortly after joining, and US 7 and Route 33 continue northwest for approximately another mile before US 7 turns off to the north. Route 33 continues northwest and west before turning north into Ridgefield.

In Ridgefield, Route 33 continues north to end at an intersection with Route 35.

In Wilton, Route 33 is a Scenic Route known as Ridgefield Road from Old Ridgewood Road #1 to the Ridgefield town line.

Route 33 was commissioned in 1932 from parts of former 1920s state highways 304 and 176. In 1967, the northern end was truncated from New York state line to the intersection with modern Route 116 in Ridgefield. In 1978, the concurrency with Route 35 was deleted and the northern end truncated from Route 116 to its current location at Route 35.

The entire route is in Fairfield County.

Location	mi	km	Destinations	Notes
Westport	0.00– 0.09	0.00– 0.14	I-95 / Route 136 – New Haven, New York City, Saugatuck	Exit 17 on I-95; to Westport station
	1.60	2.57	US 1 (Post Road) – Norwalk, Southport
	2.01	3.23	Route 57 north – Westport Center	Southern terminus of Route 57
	3.35	5.39	Route 15 / Merritt Parkway – New Haven, New York City	Exit 41 on Route 15 / Merritt Parkway
Wilton	4.67	7.52	Route 53 – Weston, Norwalk
	5.91	9.51	US 7 south to Route 15 / Merritt Parkway	Southern terminus of US 7 concurrency
	6.17	9.93	Route 106 south – Wilton Center	Southern terminus of Route 106 concurrency
	6.35	10.22	Route 106 north	Northern terminus of Route 106 concurrency
	7.18	11.56	US 7 north – Wilton station	Northern terminus of US 7 concurrency
Ridgefield	14.41	23.19	Route 35
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus