Henry Seymour Rawlinson, 1st Baron Rawlinson of Trent (February 20, 1864 – March 28, 1925) was a British First World War general most famous for his role in the Battle of the Somme of 1916.

Rawlinson was born in Trent Manor, Dorset in 1864. His father, Sir Henry Creswicke Rawlinson, was an army officer (and a reknowned scholar on the Middle East). Young Henry attended Eton and Sandhurst and entered the army in 1884 as an officer in the King's Royal Rifles in India. His first military experience was serving in Burma during an 1886 uprising.

In 1889, Rawlinson's mother died and he returned to England. He transferred to the Coldstream Guards and was promoted to Captain. He served on Kitchener's staff during the advance on Omdurman in 1898 and served with distinction in a field command in the Boer War in 1899 to 1902. Rawlinson was promoted to Lieutenant General in 1903 and named as commandant of the Army Staff College.

At the outbreak of World War I in 1914, Rawlinson took command of the British IV Corps . In 1915 he was elevated to command of the British First Army but was taken off the front after questioning higher ranks about the tactics being used. Rawlinson was assigned to Gallipoli to organize the withdrawal of British forces that had become entrenched there. He performed this task better than others had thought possible and he was recalled to the Western Front to assume command of the Fourth Army in 1916 as the plans for the Allied offensive on the Somme were being developed. For a period in 1917-18 he also commanded the Second Army.

During the war, Rawlinson was noted for his willingness to use innovative tactics. He organized one of the first major night attacks by a modern army in 1916. For a 1918 offensive, he combined attacks by airplanes and armoured units with the infantry. Rawlinson's tactics often achieved success in their area but were too localized to have a decisive affect on the war.

Following the Armistice, Parliament passed a vote of thanks to Rawlinson for his service. In 1919 he was raised to the peerage as Baron Rawlinson of Trent. He was again called on to organize an evacuation, this time of the Allied forces that had been sent to Russia to intervene in the Civil War there. In 1920 Rawlinson was made Commander-in-Chief of the British Indian Army, a post he held until his death. Rawlinson died when he took ill after playing polo and cricket on his 65th birthday in 1925.