Joseph Patrick "Joe" Kennedy, Sr. (September 6, 1888 – November 18, 1969) was a prominent American businessman and political figure, and the father of U.S. President John F. Kennedy, United States Senators Robert F. Kennedy and Edward Kennedy, Special Olympics founder Eunice Kennedy Shriver, and grandfather of US Representative Patrick Kennedy. He was a leading member of the Democratic Party and of the Irish Catholic community. He was the inaugural Chairman of the U.S. Securities and Exchange Commission (SEC), appointed by President Franklin D. Roosevelt, and later directed the Maritime Commission. Kennedy served as the United States Ambassador to Great Britain from 1938 until late 1940, including the early part of World War II.

Born to a political family in Boston, Massachusetts, Joseph Kennedy was educated at Boston Latin School and Harvard University, and embarked on a career in finance, making a large fortune as a stock market and commodity investor and by investing in real estate and a wide range of industries. Allegedly these included bootlegging, the illegal importation of alcohol into the United States during Prohibition, though these allegations have never been proven. It has been substantiated that toward the end of Prohibition, Kennedy and James Roosevelt traveled to Scotland to buy distribution rights for Scotch whisky. In addition, Kennedy had purchased spirits-importation rights from Schenley, a firm in Canada.

During World War I, he was an assistant general-manager of Bethlehem Steel and developed a friendship with Franklin D. Roosevelt, then Assistant Secretary of the Navy. Kennedy made huge profits from reorganizing and refinancing several Hollywood studios, ultimately merging several acquisitions into Radio-Keith-Orpheum (RKO) studios. After Prohibition ended in 1933, Kennedy consolidated an even larger fortune when his company, Somerset Importers, became the exclusive American agent for Gordon's Gin and Dewar's Scotch. He owned the largest office building in the country, Chicago's Merchandise Mart, giving his family an important base in that city and an alliance with the Irish-American political leadership there.