Delaware Route 71 (DE 71) is a state highway in New Castle County, Delaware. The route loops off U.S. Route 13 (US 13) from south of Townsend to Tybouts Corner, traveling to the west of US 13 by way of Townsend, Middletown, and the Summit Bridge. The route overlaps US 301 from the north end of Middletown to just north of the Summit Bridge, and also with DE 896 from Mount Pleasant to just north of the Summit Bridge, where US 301 and DE 896 continue north together to Glasgow.

DE 71 was built as a state highway during the 1920s and 1930s. By 1938, the route was designated to run from US 13 south of Townsend to US 13 in Tybouts Corner roughly along its present-day alignment. In the 1950s, DE 71 was rerouted to head to the Maryland border southwest of Middletown, with the former route south of Middletown becoming an extended DE 896. Between the 1950s and 1980s, DE 71 was signed with various alignments of US 301 and US 301S. In the 1980s, DE 71 was truncated to DE 896 in Summit Bridge before being extended back along its 1930s alignment to US 13 by the 1990s.

DE 71 heads to the northwest from US 13 on two-lane undivided Summit Bridge Road, passing through wooded areas with some homes. The road passes to the east of Townsend and interesects Pine Tree Road/Main Street near some businesses. Past Townsend, the route continues northwest into farmland, making a turn to the north. At the intersection with St. Anne's Church Road, Delaware Bicycle Route 1 (Bike Route 1) turns north to join DE 71. DE 71 enters areas of increasing residential development as it heads into the town of Middletown, where it becomes Broad Street. The road heads north through the town and intersects DE 299 (Main Street) in the commercial center of town. Here, Bike Route 1 turns west onto DE 299. From this point, the route passes more homes before passing near businesses. DE 71 crosses Norfolk Southern's Delmarva Secondary at-grade and intersects US 301 immediately after.

DE 71 heads north concurrent with US 301 on Summit Bridge Road, passing near some businesses and a housing development before leaving Middletown. The road runs a short distance to the west of the Norfolk Southern rail line as it continues farmland with some scattered residential and commercial development. In Mount Pleasant, DE 896 joins US 301/DE 71 from the east and the road widens from a two-lane undivided road to a four-lane, divided highway. The road passes a few businesses before heading between the Summit Airport to the west and housing developments to the east. US 301/DE 71/DE 896 heads to the northwest through farm fields before turning to the west and passing a residential subdivision to the south. In the unincorporated community of Summit Bridge, the road intersects the northern terminus of DE 15, where Bike Route 1 joins the road again. Past this intersection, US 301/DE 71/DE 896 turns north and crosses over the Chesapeake and Delaware Canal on the Summit Bridge.

Past the Summit Bridge, the road passes through woods and passes under Chesapeake City Road near the Delaware Veterans Memorial Cemetery. DE 71 splits from US 301/DE 896 and Bike Route 1 by heading to the southeast on two-lane undivided Red Lion Road. The road passes a mix of woods and homes as it becomes the southern boundary of Lums Pond State Park and turns east into woodland. The route turns northeast through more of the state park before entering into a mix of farmland and homes. DE 71 passes through the community of Kirkwood and crosses the Norfolk Southern Delmarva Secondary again, continuing into wooded areas of suburban residential development, crossing DE 72. The route continues northeast near a mix of farms and woods with some homes, crossing Norfolk Southern's Delaware City Secondary. From here, the road passes more suburban residences and reaches the community of Red Lion, where it crosses DE 7. The final stretch of DE 71 heads northeast past more housing subdivisions toward its northern terminus at US 13 in Tybouts Corner. This intersection is within an interchange between US 13 and DE 1, where DE 1 merges off US 13. Direct access is provided from southbound DE 1 to DE 71 just before the intersection with US 13.

DE 71 has an annual average daily traffic count ranging from a high of 24,445 vehicles at the DE 896 intersection in Mount Pleasant to a low of 4,351 vehicles at the DE 7 intersection. The portion of DE 71 concurrent with US 301 is part of the National Highway System.

What is now DE 71 originally existed as a county road by 1920, with the portion south of Townsend proposed as a state highway at this time. By 1924, the entire length of the present route was paved, with the portion from the Summit Bridge to Kirkwood proposed as a state highway and the portion from Kirkwood to Tybouts Corner improved to a state highway. A year later, the state highway had been completed south of Townsend and between Mt. Pleasant and Kirkwood. By 1931, the remainder became a state highway. When Delaware started numbering state highways by 1936, this road remained unnumbered. By 1938, DE 71 was designated to run from US 13 south of Townsend north to US 13 in Tybouts Corner, following roughly the same alignment it does today.

By 1957, DE 71 was rerouted to follow DE 299 southwest from Middletown before splitting from that route and reaching the Maryland border, where it connected to MD 71. Also, DE 896 was extended south from Summit Bridge to follow DE 71 to Middletown and then continue along the former DE 71 through Townsend to US 13. By 1959, US 301 was designated along DE 71/DE 299 between the Maryland border and Middletown and US 301S was designated along DE 71 from Middletown to Tybouts Corner. The route was realigned to a new Summit Bridge a short distance to the west in 1960, following new roads that led to the bridge. As a result of this, US 301S/DE 71 was designated onto a former piece of DE 896 between the new alignment and Red Lion Road to the east, with the rest of the former alignment becoming a dead end road south to the canal and the former alignment south of the canal becoming a local road serving the community of Summit. By 1971, US 301 was shifted to follow what had been US 301S between Middletown and Summit Bridge, with US 301S remaining along DE 71 between Summit Bridge and Tybouts Corner. By 1984, DE 896 was rerouted to run from Mount Pleasant to Boyds Corner, with the route being removed from DE 71 from Mt. Pleasant to Middletown and the segment from Middletown to south of Townsend, which was the original routing of DE 71, becoming unnumbered. A year later, US 301N was rerouted onto the newly aligned DE 896 and US 13 between Mt. Pleasant and Tybouts Corner and US 301S was extended south along DE 71/DE 896 from Summit Bridge to Mt. Pleasant. DE 71 was truncated to Summit Bridge by 1987, also at which time US 301S was removed from DE 71. By 1990, DE 71 was extended back south along its original alignment to again end at US 13 south of Townsend. US 301 was realigned to follow the route between Mt. Pleasant and Summit Bridge by 1994.

The entire route is in New Castle County.