Kathleen Agnes "Kick" Kennedy (February 20, 1920 – May 13, 1948), was the fourth child and second daughter of Joseph P. Kennedy, Sr. andRose Kennedy. She was a sister of future U.S. President John F. Kennedy and widow of the heir apparent to the Dukedom of Devonshire.

When President Franklin D. Roosevelt appointed Joseph P. Kennedy, Sr. ambassador to the United Kingdom, Kick spent a year and a half living inLondon. She was educated in London at Queen's College.

Kathleen later worked at Cissy Patterson's newspaper, the Washington Times-Herald, in 1940, writing a column titled, "Did you happen to see ….. ?".[1] In 1943, she returned to England to work in a center for servicemen set up by the Red Cross. Despite the opposition of her Catholic mother, she married William Cavendish, Marquess of Hartington, an Anglican and the eldest son and heir apparent of the 10th Duke of Devonshire, on May 6, 1944. Her eldest brother, Joseph P. Kennedy, Jr., was the only member of the Kennedy family to attend the ceremony. Four months after their marriage, her husband was killed in action while serving in World War II. Her husband's younger brother Lord Andrew Cavendish, married to Deborah Mitford of the famous Mitford sisters, thus became the heir apparent to the dukedom.

Popular on the London social circuit and admired by many for her high spirits, Kathleen eventually became romantically involved with Peter Wentworth-Fitzwilliam, 8th Earl Fitzwilliam.[2] The couple planned to wed after Lord Fitzwilliam's divorce; however, while on a trip to the south of France, both were killed as the result of an airplane crash in Saint-Bauzile, Ardèche, France.

Only Kick's father represented the family at her funeral. Rose did not attend and, allegedly, discouraged her daughter's siblings from attending as well. She was later quoted as saying her daughter's death was "God casting a finger."

Kick is buried in the Cavendish family plot at Saint Peter's Church in Edensor, England, near Chatsworth in Derbyshire. The gymnasium atManhattanville College is named in her honor. Her brother John F. Kennedy visited the grave shortly before his own death in 1963. Robert F. Kennedynamed his eldest daughter in honor of her