Henry Denis Hauenstein, MM was an Australian national representative rower and a World War I infantry officer. He was a three-time Australian national champion rower who competed for Australasia at the 1912 Summer Olympics in the men's eight. He was a member of the Australian men's selection eight which won the Grand Challenge Cup at the Henley Royal Regatta of 1912. He saw active service on the Western Front where he won the Military Medal and was a member of the AIF crew which at war's end, won at the 1919 Peace Regatta and brought the King's Cup to Australia.

The men's eight was a rowing event held as part of the Rowing at the 1912 Summer Olympics programme. It was the fourth appearance of the event. The competition was held from Wednesday to Friday, 17 to 19 July 1912. Ninety-nine rowers from eight nations competed. Nations were still permitted to have two boats each in the event.