| Birth Place: | Sankt Gallen, Switzerland |
| Height: | 168 cm |
| Weight: | 57 kg |
| Sport: | Equestrianism |
| Event: | Show jumping |
| Club: | VEP, Elgg |
| Show-Medals: | yes |
Monica Bachmann-Weier (born 17 April 1942) is a retired Swiss horse rider. She competed in the individual and team show jumping at the 1968 and 1972 Summer Olympics and placed fifth-seventh. Her husband Paul Weier is also an Olympic show jumper.