| Harold Koch Boysen | |
| Birth Date: | 2 November 1891 |
| Death Date: | 20 February 1963 |
| Birth Place: | Lake Benton, Minnesota, United States |
| Death Place: | Harris County, Texas, USA |
| Allegiance: |  United States |
| Branch: | Royal Air Force (United Kingdom) |
| Serviceyears: | 1917 - 1918 |
| Rank: | Lieutenant |
| Unit: | Royal Air Force |
| Battles: | World War I |
| Awards: | Silver Medal for Military Valor |
Lieutenant Harold Koch Boysen was a World War I flying ace credited with five aerial victories.[1] [2]
Boysen joined the Royal Flying Corps in June 1917. After training, he was assigned to 66 Squadron to fly a Sopwith Pup. He would not have any success until the unit re-equipped with Sopwith Camels and transferred fronts from France to northern Italy.[2] He scored a victory in December 1917. In January 1918, he crashed while landing in a fog, and was injured.[1] Upon recovery, he then scored four more times in May 1918, including one win shared with Lieutenant Christopher McEvoy.[1]