| Louise Ørnstedt | |
| Fullname: | Louise Ørnstedt |
| Strokes: | Backstroke |
| Club: | odenseanske FORWARD |
| Birth Date: | 1985 3, df=y |
| Birth Place: | Odense, Syddanmark |
Louise Ørnstedt (born 23 March 1985) was a Danish backstroke swimmer who competed at the 2000 and 2004 Olympics.
She retired from swimming in August 2007 due to persistent shoulder problems.