Delaware Route 14 (DE 14) is a state highway in the southern part of Kent County, Delaware. The route runs from the Maryland border near Burrsville, Maryland, where it continues as Maryland Route 317 (MD 317), east to DE 1 in Milford. The route passes through Harrington, where it intersects U.S. Route 13 (US 13), and passes to the north of Houston before coming to Milford, where it intersects DE 15, US 113, and DE 1 Business (DE 1 Bus.). DE 14 has a truck bypass of Harrington known as DE 14 Truck.

DE 14 was first designated by 1936 to run from the Maryland border near Burrsville east to DE 26 in Bethany Beach. By 1939, the road was extended south to Fenwick Island. In the 1940s, the road was realigned to bypass Rehoboth Beach. The route between Nassau and Rehoboth Beach was widened into a divided highway in the 1950s, with all of DE 14 southeast of Milford being upgraded to a divided highway by the 1970s. In 1977, most of DE 14 east of Milford was replaced with DE 1, with the eastern terminus being realigned to its current location by 1984.

DE 14 begins at the Maryland border, where it continues west into that state as MD 317. From the state line, the route heads east on two-lane undivided Vernon Road, passing through a mix of farmland and woodland with occasional homes. The road curves to the northeast before heading east as Walt Messick Road and entering Harrington. DE 14 passes through commercial areas with some homes before intersecting DE 14 Truck, which bypasses Harrington to the south. At this point, DE 14 heads northeast on Commerce Street, passing homes and heading into the commercial downtown. Here, the route turns east onto Clark Street and crosses Norfolk Southern's Delmarva Secondary railroad line, continuing through residential areas with some businesses. On the eastern edge of Harrington, DE 14 intersects US 13 in a commercial area, at which point DE 14 Truck returns to the route.

Past this intersection, the route leaves Harrington and becomes Milford Harrington Highway, heading through a mix of farms and woods with some residential development. The road continues east through more rural areas, passing to the north of Houston. Farther east, DE 14 heads southeast and intersects the southern terminus of DE 15, heading into Milford. The road heads into commercial areas and gains a center left-turn lane, coming to an intersection with US 113. Past this intersection, the route becomes Northwest Front Street and passes homes and businesses a short distance to the north of Norfolk Southern's Indian River Secondary railroad line and Silver Lake along the Mispillion River, narrowing back to two lanes. The road curves to the east and heads through the downtown of Milford, becoming Northeast Front Street at the intersection with North Walnut Street. DE 14 passes through more commercial areas a short distance to the north of the Mispillion River, curving northeast and coming to an intersection with DE 1 Bus. Past this intersection, the route heads through areas of farmland with some commercial development, ending at an intersection with the DE 1 bypass of Milford.

DE 14 has an annual average daily traffic count ranging from a high of 14,121 vehicles at the western edge of Milford to a low of 1,804 vehicles at the eastern terminus at DE 1. None of DE 14 is part of the National Highway System.

What would become DE 14 originally existed as a county road between the Maryland border in Burrsville and Rehoboth Beach by 1920. By 1924, the road had been completed as a state highway between Burrsville and Milford and was proposed as one between Nassau and Rehoboth Beach. A year later, the state highway was completed between Milford and Cedar Creek and from Nassau to just west of Rehoboth Beach, with the sections between Cedar Creek and Nassau and into Rehoboth Beach under proposal. By 1931, the state highway between Milford and Rehoboth Beach was completed, with a section north of Bethany Beach completed as a gravel road. In addition, the road between Rehoboth Beach and Dewey Beach was paved. When Delaware designated its state highway system by 1936, DE 14 was designated to run from the Maryland border in Burrsville east to DE 26 in Bethany Beach, following a newly-completed road along the Atlantic Ocean between Dewey Beach and Bethany Beach. By 1939, a southern extension of DE 14 was built between Bethany Beach and the Maryland border in Fenwick Island as a gravel road, this was paved by 1942. Also by 1942, DE 14 was realigned to bypass Rehoboth Beach to the southwest.

The route was widened into a divided highway between Nassau and Rehoboth Beach by 1954, with the route being moved to a new alignment to bypass Wescoats Corner, removing a concurrency with DE 18 (now US 9 Bus.). By 1966, DE 14A was designated onto the former alignment of DE 14 through Rehoboth Beach. The divided highway portion of DE 14 was extended north to DE 16 and between the Indian River Inlet and South Bethany by 1967. The route was widened into a divided highway between Dewey Beach and the Indian River Inlet by 1969. By 1971, a divided highway was completed linking DE 14 southeast of Milford to US 113 north of Milford, bypassing Milford. By 1973, construction was underway to make DE 14 a divided highway from the Milford Bypass to DE 16, which included a bypass of Argos Corner; this was completed in 1974. In 1974, DE 1 was signed concurrent with DE 14 east of Milford. In 1977, DE 14 was truncated to Milford, with DE 1 replacing the route between Fenwick Island and the south end of the Milford Bypass and DE 1 Bus. becoming concurrent with route between the Milford Bypass and Northeast Front Street. As a result of this, DE 14A was renumbered to DE 1A. DE 14 was realigned to follow Northeast Front Street to end at DE 1 on the Milford Bypass by 1984.

The entire route is in Kent County.

Delaware Route 14 Truck (DE 14 Truck) is a truck bypass of DE 14 in Harrington. The route heads south from DE 14 on two-lane undivided Farmington Road, leaving Harrington and heading through farmland. DE 14 Truck turns east onto Tower Hill Road and crosses Norfolk Southern's Delmarva Secondary railroad line before coming to an intersection with US 13. At this point, the truck route turns north to form a concurrency with US 13 on Dupont Highway, a four-lane divided highway. The road heads back into Harrington and runs through commercial areas, passing to the east of the Delaware State Fairgrounds, which is where the Delaware State Fair is held and the Harrington Raceway & Casino is located. US 13/DE 14 Truck crosses Norfolk Southern's Indian River Secondary, with the median widening to include businesses in it. DE 14 Truck ends at another intersection with DE 14. DE 14 Truck was designated in 2008 following an $8.5 million, year-long project that improved the roads the truck route follows.

Delaware Route 14A (DE 14A) was the designation of the former alignment of DE 14 through Dewey Beach and Rehoboth Beach. The route began at DE 14 in Dewey Beach and headed north into Rehoboth Beach, where it turned to the west and intersected DE 14 again west of Rehoboth Beach. The route was a former segment of DE 14 that was bypassed by 1942 and received the DE 14A designation by 1966. By 1974, the route would become cosigned with DE 1A, with DE 1A replacing DE 14A in 1977.