Delaware Route 72 (DE 72) is a state highway located in New Castle County, Delaware. The route runs from DE 9 near Delaware City north to DE 7 in Pike Creek. The highway runs through suburban areas of northern New Castle County, passing through the eastern part of Newark. DE 72 intersects U.S. Route 13 (US 13), DE 7, and DE 1 near Delaware City, DE 71 in Williamsburg, US 40 east of Glasgow, and DE 4, DE 2, and DE 273 in Newark. Parts of DE 72 were built as a state highway during the 1930s. By the 1940s, the route was designated from DE 2 in Newark north to DE 7 in Pike Creek along Paper Mill Road. The route was extended south to DE 9 in the 1960s. In 1980, the alignment was shifted to the east through Newark to bypass an at-grade railroad crossing on Chapel Street.

New Castle County is the northernmost of the three counties of the U.S. state of Delaware. As of the 2020 census, the population was 570,719, making it the most populous county in Delaware, with nearly 60% of the state's population of 989,948. The county seat is Wilmington, which is also the state's most populous city.