| Walter Carl Simon | |
| Birth Date: | 14 September 1890[1] |
| Death Date: | 16 May 1971 |
| Birth Place: | New Orleans, Louisiana, USA |
| Death Place: | Kingsport, Tennessee, USA |
| Allegiance: |  United States |
| Branch: | Royal Air Force (United Kingdom) |
| Rank: | 2nd Lieutenant |
| Unit: | Royal Air Force |
| Battles: | World War I |
| Awards: | Distinguished Flying Cross |
Lieutenant Walter Carl Simon (1890–1971) was a World War I flying ace credited with eight aerial victories.
Flying a Bristol F.2 Fighter for the British, he and his observer scored five victories on the single day of 30 July 1918; he thus became the first American "ace in a day". When the war ended, he went to Lima, Peru, where he was promoted to the rank of 1st Lieutenant and became Vice-director of the Naval Flying School at Ancon, headed by Captain Juan Swayne Leguia, former RAF pilot in World War I and son of Augusto B. Leguia, president of Peru.[2]