Joseph Patrick Kennedy (September 6, 1888 – November 18, 1969) was an American businessman, investor, philanthropist, and politician. He is known for his own political prominence as well as that of his children and was the ambitious patriarch of the Kennedy family, which included Senator and President John F. Kennedy, Attorney General and Senator Robert F. Kennedy, and longtime Senator Ted Kennedy.

Kennedy was born into a political family in East Boston, Massachusetts. He made a large fortune as a stock and commodity market investor, and later rolled over his proceeds by dedicating a substantial amount of his wealth into investment-grade real estate and a wide range of privately controlled businesses across the United States. During World War I he was an assistant general manager of a Boston area Bethlehem Steel shipyard; through that position he became acquainted with Franklin D. Roosevelt, who was the Assistant Secretary of the Navy. In the 1920s Kennedy made huge profits by reorganizing and refinancing several Hollywood studios; several acquisitions were ultimately merged into Radio-Keith-Orpheum (RKO) studios. Kennedy increased his fortune with distribution rights for Scotch whisky. He owned the largest privately owned building in the country, Chicago's Merchandise Mart.

Kennedy was a leading member of the Democratic Party and of the Irish Catholic community. President Roosevelt appointed Kennedy to be the first chairman of the Securities and Exchange Commission (SEC), which he led from 1934 to 1935. Kennedy later directed the United States Maritime Commission. He served as the United States Ambassador to the United Kingdom from 1938 to late 1940. With the outbreak of World War II in September 1939, Kennedy was pessimistic about Britain's ability to survive attacks from Germany. During the Battle of Britain in November 1940, Kennedy publicly suggested, "Democracy is finished in England. It may be here [in the United States]." After a controversy regarding this statement, Kennedy resigned his position.

Kennedy was married to Rose Fitzgerald; the couple had nine children. During his later life he was heavily involved in the political careers of his sons. Three of Kennedy's sons attained distinguished political positions: John served as a U.S. senator from Massachusetts and as the 35th president of the United States, Robert as the U.S. attorney general and as a U.S. senator from New York, and Ted as a U.S. senator from Massachusetts.

Joseph Patrick Kennedy was born on September 6, 1888, at 151 Meridian Street in East Boston, Massachusetts. Kennedy was the elder son of Mary Augusta (née Hickey) Kennedy and businessman and politician Patrick Joseph "P.J." Kennedy. Kennedy attended Boston Latin School, where he excelled at baseball and was elected class president before graduating in 1908.

Kennedy then attended Harvard College, where he gained admittance to the prestigious Hasty Pudding Club but was not invited to join the Porcellian Club. Kennedy graduated in 1912 with a bachelor's degree in economics.

Kennedy set his future sights on embarking on a business career upon his graduation from Harvard. During his mid to late 20s, he made a large fortune as an active commodity and stock investor; he then reinvested much of his proceeds into film studios, real estate, and shipping lines. Although Kennedy never built a significant business from scratch, his timing as both buyer and seller was excellent.

Various criminals, such as Frank Costello, boasted that they worked with Kennedy in mysterious bootlegging operations during Prohibition. Although his father was in the whisky importation business, scholars dismiss the claims. The most recent and most thorough biographer David Nasaw asserts that no credible evidence has been found to link Kennedy to bootlegging activities. When Fortune magazine published its first list of the richest people in the United States in 1957, it placed Kennedy in the $200–400 million group, equivalent to about $3.2 billion in 2023.