Louis Francis Albert Victor Nicholas Mountbatten, 1st Earl Mountbatten of Burma (born Prince Louis of Battenberg; 25 June 1900 – 27 August 1979), commonly known as Lord Mountbatten, was a British statesman, Royal Navy officer and close relative of the British royal family. He was born in the United Kingdom to the prominent Battenberg family. He was a maternal uncle of Prince Philip, Duke of Edinburgh, and a second cousin of King George VI. He joined the Royal Navy during the First World War and was appointed Supreme Allied Commander, South East Asia Command, in the Second World War. He later served as the last Viceroy of India and briefly as the first Governor-General of the Dominion of India.

Mountbatten attended the Royal Naval College, Osborne, before entering the Royal Navy in 1916. He saw action during the closing phase of the First World War, and after the war briefly attended Christ's College, Cambridge. During the interwar period, Mountbatten continued to pursue his naval career, specialising in naval communications. Following the outbreak of the Second World War, he commanded the destroyer HMS Kelly and the 5th Destroyer Flotilla. He saw considerable action in Norway, in the English Channel, and in the Mediterranean. In August 1941, he received command of the aircraft carrier HMS Illustrious.

In early 1942 he was appointed chief of Combined Operations and a member of the Chiefs of Staff Committee by Prime Minister Churchill. He organised the raids on St Nazaire and Dieppe. In August 1943, Mountbatten became Supreme Allied Commander South East Asia Command and oversaw the recapture of Burma and Singapore from the Japanese by the end of 1945. For his service during the war, Mountbatten was created viscount in 1946 and earl the following year.

In February 1947, Mountbatten was appointed Viceroy and Governor-General of India by the Labour government under Prime Minister Attlee. In this capacity he oversaw the Partition of India into India and Pakistan. He then served as the first Governor-General of the Union of India until June 1948 and played a significant role in persuading princely states to accede to India. In 1952, Mountbatten was appointed commander-in-chief of the British Mediterranean Fleet and NATO Commander Allied Forces Mediterranean. From 1955 to 1959, he was First Sea Lord, a position that had been held by his father, Prince Louis of Battenberg, some forty years earlier. Thereafter he served as chief of the Defence Staff until 1965, making him the longest-serving professional head of the British Armed Forces to date. During this period Mountbatten also served as chairman of the NATO Military Committee for a year.

In August 1979, Mountbatten was assassinated by a bomb planted aboard his fishing boat in Mullaghmore, County Sligo, Ireland, by members of the Provisional Irish Republican Army. He received a ceremonial funeral at Westminster Abbey and was buried in Romsey Abbey in Hampshire.

Mountbatten, then named Prince Louis of Battenberg, was born on 25 June 1900 at Frogmore House in the Home Park, Windsor, Berkshire. He was the youngest child and the second son of Prince Louis of Battenberg and his wife Princess Victoria of Hesse and by Rhine. Mountbatten's maternal grandparents were Louis IV, Grand Duke of Hesse, and Princess Alice of the United Kingdom, who was a daughter of Queen Victoria and Prince Albert of Saxe-Coburg and Gotha. His paternal grandparents were Prince Alexander of Hesse and by Rhine and Julia, Princess of Battenberg. Mountbatten's paternal grandparents' marriage was morganatic because his grandmother was not of royal lineage; as a result, he and his father were styled "Serene Highness" rather than "Royal Highness", were not eligible to be titled Princes of Hesse, and were given the less exalted Battenberg title. Mountbatten's elder siblings were Princess Alice of Battenberg (mother of Prince Philip, Duke of Edinburgh), Princess Louise of Battenberg (later Queen Louise of Sweden), and Prince George of Battenberg (later George Mountbatten, 2nd Marquess of Milford Haven).

Mountbatten was baptised in the large drawing room of Frogmore House on 17 July 1900 by the Dean of Windsor, Philip Eliot. His godparents were Queen Victoria (his maternal great-grandmother), Nicholas II of Russia (his maternal uncle through marriage and paternal second cousin, represented by the child's father) and Prince Francis Joseph of Battenberg (his paternal uncle, represented by Lord Edward Clinton). He wore the original 1841 royal christening gown at the ceremony.

Mountbatten's nickname among family and friends was "Dickie"; however "Richard" was not among his given names. This was because his great-grandmother, Queen Victoria, had suggested the nickname of "Nicky", but to avoid confusion with the many Nickys of the Russian Imperial Family ("Nicky" was particularly used to refer to Nicholas II, the last Tsar), "Nicky" was changed to "Dickie".