Hyannis is the largest of the seven villages in the town of Barnstable, Massachusetts, in the United States. It is the commercial and transportation hub of Cape Cod and was designated an urban area as of the 1990 census. Because of this, many refer to Hyannis as the "Capital of the Cape". It contains a majority of the Barnstable Town offices and two important shopping districts, the historic downtown Main Street and the Route 132 Commercial District, including Cape Cod Mall and Independence Park, headquarters of Cape Cod Potato Chips. Cape Cod Hospital in Hyannis is the largest on Cape Cod.
Hyannis is a highly important tourist destination and the primary ferry boat and general aviation link for passengers and freight to Nantucket Island. Hyannis also provides secondary passenger access to the island of Martha's Vineyard, with the primary passenger access to Martha's Vineyard being located in Woods Hole, a village in the nearby town of Falmouth. Due to its large natural harbor, Hyannis is the largest recreational boating and second largest commercial fishing port on Cape Cod, behind only Provincetown.
The JFK Hyannis Museum in the old Town Hall on Main St. focuses on John F. Kennedy's time spent in the town. There is a memorial to President Kennedy on the Lewis Bay waterfront that was erected by Barnstable citizens in 1966. The memorial includes a fountain and a field-stone monument with the presidential seal and JFK inscription: "I believe it is important that this country sail and not sit still in the harbor." President-elect John F. Kennedy gave his victory speech on November 9, 1960, at the former Hyannis Armory, which is in the National Register of Historic Places.
The village is the namesake of the former United States Naval ship .