Sir William Napier, 3rd Baronet

Lt Col Sir William Lennox Napier, 3rd Baronet of Merrion Square, (12 October 1867 – 13 August 1915), was a British baronet and soldier.

He joined the Sussex Artillery Volunteers in 1888. He was commander of the 7th Battalion, Royal Welch Fusiliers, as part of the Territorial Army.

He retired in 1912, but offered his services on the outbreak of the First World War in August 1914, and was commissioned as Major, 4th South Wales Borderers, on 24 September 1914 in command of "A" Company.

He was killed by a sniper on 13 August 1915 in the Battle of Gallipoli, Turkey, aged 47, and is buried in 7th Field Ambulance Cemetery.

He was married to Lady Mabel E. G. Napier (née Forster).

He succeeded to the Baronetage of Merrion Square in 1884 on the death of Sir Joseph Napier, 2nd Baronet (1841–1884), and was succeeded by Sir Joseph William Lennox Napier, 4th Baronet (1895–1986).