The Christina River is a tributary of the Delaware River, approximately 35 miles (56 km) long, in northern Delaware. It also flows through small areas of southeastern Pennsylvania and northeastern Maryland. Near its mouth, the river flows past downtown Wilmington, Delaware, forming the city's harbor for traffic on the Delaware River. The Port of Wilmington, opened in 1923 at the river's mouth, handles international cargo and trade.

Wilmington is the largest city in the U.S. state of Delaware. The city was built on the site of Fort Christina, the first Swedish settlement in North America. It lies at the confluence of the Christina River and Brandywine Creek, near where the Christina flows into the Delaware River. It is the county seat of New Castle County and one of the major cities in the Delaware Valley metropolitan area. Wilmington was named by Proprietor Thomas Penn after his friend Spencer Compton, Earl of Wilmington, who was prime minister during the reign of George II of Great Britain.