Thain Wendell MacDowell, VC, DSO (September 16, 1890 – March 28, 1960), was a Canadian soldier.

One of four soldiers to earn the Victoria Cross in the Battle of Vimy Ridge, one of two to survive the battle and the only one to survive the war, (the others were Ellis Wellwood Sifton, William Johnstone Milne and John George Pattison), MacDowell was 26 years old, and a captain in the 38th (Ottawa) Battalion, Canadian Expeditionary Force during the First World War when he was awarded the Victoria Cross.

On 9 April 1917 at Vimy Ridge, France, Captain MacDowell, with the assistance of two runners (company orderlies, Pvts.

Although wounded in the hand, MacDowell continued for five days to hold the position gained, in spite of heavy shellfire, until eventually relieved by his battalion.

After the war, Colonel MacDowell served as an executive of several mining and chemical companies, and from 1923 to 1928, he acted as private secretary to the Minister of National Defence.

He also had three grand children: A. Stuart, Patricia E, And Kenneth R. He died in Nassau, the Bahamas, on 28 March 1960.