| Santiago Sinclair | |
| Birth Date: | 1927 12, df=y |
| Birth Place: | Valdivia, Chile |
| Office: | Designed Senator |
| Term Start: | 11 March 1990 |
| Term End: | 11 March 1998 |
| Successor: | Julio Canessa |
| Office1: | Member of the Military Junta |
| Term Start1: | 30 November 1988 |
| Term End1: | 2 January 1990 |
| President1: | Augusto Pinochet |
| Predecessor1: | Humberto Gordon |
| Successor1: | Jorge Lucar |
| Alma Mater: | Bernardo O'Higgins Military Academy |
| Spouse: | Doris Manley |
| Children: | Four |
Santiago Sinclair Oyaneder (born 29 December 1927) was a Chilean Army general and member of the Government Junta from 1988 to 1990 that ruled Chile from 1973–1990.[1]