Sir James Somerville (17 July 1882 - 19 March 1949) was a British Admiral during World War II.

Born in Weybridge, Surrey, he entered the Royal Navy as a cadet in 1898 and achieved the rank of lieutenant by 1904. Somerville became the Navy's leading radio specialist and served at Gallipoli during World War I, where he earned the Distinguished Service Order for his efforts.

Somerville stayed in the service after the war, and in 1921 he was promoted to captain. Somerville served as Director of the Admiralty's Signal Department from 1925 to 1927, and as a Naval Instructor at the Imperial Defence College from 1929 - 1931. He was promoted to commodore in 1932 and to rear admiral in 1933. Somerville commanded the Mediterranean Fleet destroyer flotillas from 1936 to 1938, and during the Spanish Civil War helped protect Majorca from the Republicans. From 1938 to 1939 he served in the East Indies before retiring in 1939. However, he was recalled to duty on special service to the Admiralty later that year with the start of World War II, and for the next year performed important work on naval radar development.

In May 1940 Somerville served under Admiral Bertram Ramsay at Dunkirk. His next major assignment was as naval commander of Force H based in Gibraltar, which included the carrier Ark Royal and the battlecruiser Hood. After Henri-Philippe Petain signed an armistice with Germany on 22 June 1940, Winston Churchill gave Somerville the task of neutralizing the French fleet at Mers-el-Kébir in North Africa. On 9 February 1941 Somerville organized a bombardment raid on Genoa and played an important role in the pursuit and sinking of the Bismarck on 26 May 1941. He received the KBE in 1941 for his successes with Force H.

Sommerville became commander of the British Eastern Fleet in March 1942. He was based at Ceylon in the Indian Ocean until the Japanese advance forced him to shift to Kilindini, Kenya. In 1944, with re-inforcements, he was able to go on the offensive in a series of strikes in the Japanese-occupied Dutch East Indies.

Sommerville was replaced as commander of the Eastern Fleet by Admiral Bruce Fraser in August 1944, and two months later was placed in charge of the British Admiralty Delegation in Washington from 1944 to 1945. He was promoted to Admiral of the Fleet in May 1945.

Following the war he was made Lord Lieutenant of Somerset in 1946. He retired from the service and lived in Dinder House, Somerset where he died on 19 March 1949.