The Louie B. Nunn Cumberland Expressway is a 88.4-mile (142.3 km) freeway in the U.S. state of Kentucky, extending from Barren County in the west to Somerset in the east. It is one of seven named highways designated in Kentucky's parkway system.

The expressway begins at Interstate 65 (exit 43) interchange between Smiths Grove and Park City. It travels east through rolling farmland to its eastern terminus at US 27 on the north side of Somerset. The road parallels Kentucky Route 80 for its entire length. The expressway passes the cities of Glasgow, Edmonton, Columbia, and Russell Springs. It passes near two popular state parks: Lake Cumberland State Resort Park and Barren River Lake State Resort Park. The length of the expressway is designated unsigned Kentucky Route 9008 (LN 9008).

The road is named after Louie B. Nunn, a former Kentucky governor from Barren County, who was instrumental in the road's creation. Originally called the Cumberland Parkway from its opening in 1972–1973, it was renamed for Nunn in 2000.

The Nunn Parkway, as with all nine parkways, was originally a toll road. By Kentucky state law, toll collection ceases when enough toll has been collected or funds received from other sources, such as a legislative appropriation, to pay off the construction bonds for the parkway. In the case of the Nunn, toll booths were removed in 2003 because of a bill in the United States Congress sponsored by Hal Rogers (R-KY), which included an appropriation to pay off the bonds on the parkway, as well as those of the Daniel Boone Parkway in southeastern Kentucky. The state legislature then renamed the Boone Parkway for Rogers, which sparked controversy among residents of the region and the offspring of Boone. Nunn tried to calm the controversy by suggesting the state rename the Nunn Parkway for Rogers instead, restoring the Boone name, saying that the Cumberland Parkway had been named for Nunn without his consent.

The parkway had three toll plazas upon opening in 1973. A fourth one opened at the Nancy exit on the eastbound on-ramp and westbound off-ramp when that interchange opened in the 1980s.

Exit or MM	Location	Through cars charge	Enter east or leave west	Enter west or leave east	Notes
3	near Bon Ayr (Barren County)	30 cents	N/A		Toll Plaza office originally located on Oak Grove Church Road off KY 255
27	Edmonton	80 cents	50 cents	30 cents
62	Russell Springs	90 cents	60 cents	30 cents
78	Nancy (Pulaski County)	Free	20 cents	Free

Presumably, the Nunn Parkway was built to Interstate Highway standards at its time of construction aside from some at-grade intersections and traffic signals near its east end, which were eliminated in 2010 by constructing a northwestern bypass around Somerset. The old routing was utilized as part of the construction projected that rerouted both Kentucky Route 80 and Kentucky Route 914. The east end of the expressway is currently a partial cloverleaf at US 27. The bypass was constructed as part of the now-cancelled I-66 proposed extension through Kentucky.

On May 28, 2015, a new interchange was opened west of Glasgow to serve the western extension of the Veterans Outer Loop. The eastern extension of that road has been opened in early 2012, complete with the opening of exit 15, which serves the eastern extension of Veterans Outer Loop, designated at KY 1519. The state highway designation for the western extension was announced as Kentucky Route 3600. Upon completion of the new western extension of the Veterans Outer Loop, it includes the new on- and off-ramps of the Cumberland Expressway, and a new at-grade intersection with Kentucky Route 1297.

The Glasgow interchange is one of seven new interchanges that have opened along the expressway since 2010. Another interchange is proposed at Kentucky Route 249 as well.

In 2021, state legislation renamed the then Cumberland Parkway to an expressway. Road signage has, as of 2024, not been updated to reflect this change.

Interstate 365
Location	Park City–Somerset
Length	88.376 mi (142.227 km)

On August 5, 2021, Congress released a new infrastructure bill that proposed to designate the whole length of the Cumberland Expressway as a Future Interstate, with the designation of I-365. The designation would need approval from AASHTO, the FHWA, and upgrades of several interchanges and some improvements before the designation could be implemented.

County	Location	mi	km	Exit	Destinations	Notes
Barren	​	0.0	0.0	1A-B	I-65 – Bowling Green, Nashville, Elizabethtown, Louisville	Western terminus; I-65 exit 43; signed as exits 1A (north) & 1B (south); trumpet interchange.
	Glasgow	8.7	14.0	8	KY 3600 (Veterans Outer Loop) to KY 90 – Glasgow, Cave City	Opened May 28, 2015
		11.4	18.3	11	US 31E – Glasgow, Scottsville
		12.904	20.767		KY 249	Proposed interchange
		14.0	22.5	14	KY 90 – Glasgow, Burkesville
		15.3	24.6	15	KY 1519 (Veterans Outer Loop) to US 68 – Glasgow	Constructed in the 2011-12 fiscal year
Metcalfe	Edmonton	27.4	44.1	27	US 68 / KY 80 – Edmonton	Cloverleaf interchange; will be reconfigured to a standard diamond
		29.7	47.8	29	US 68 to KY 3524 – Edmonton, Greensburg	Completed October 28, 2013
Adair	Columbia	46.0	74.0	46	KY 61 – Columbia, Burkesville
		48.8	78.5	49	KY 55 – Columbia
Russell	Russell Springs	62.4	100.4	62	US 127 – Jamestown, Russell Springs	Originally a cloverleaf interchange; reconstructed as a diamond interchange in 2015
	​	70.7	113.8	70	KY 910 – Eli	Opened in 2019
Pulaski	​	78.3	126.0	78	KY 80 – Nancy
	Somerset	86.1	138.6	86	KY 914 east to KY 80 – Somerset, Burnside	Opened in 2010
		88.2	141.9	88	US 27 – Somerset, Lexington	Opened in 2010; Partial Cloverleaf interchange; signed as exits 88A (south) and 88B (north); eastern terminus of parkway, ghost ramps exist
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

• KentuckyRoads.com — Louie B. Nunn Cumberland Parkway
• Exit Guide for Nunn Parkway