| St Mary's Catholic High School | |
| Coordinates: | 53.4951°N -2.4646°W |
| Established: | c. 1960 |
| Type: | Voluntary aided school |
| Religious Affiliation: | Roman Catholic |
| Head: | Andrew Dawson |
| Address: | Manchester Road |
| City: | Astley |
| County: | Greater Manchester |
| Country: | England |
| Postcode: | M29 7EE |
| Local Authority: | Wigan |
| Ofsted: | yes |
| Urn: | 106538 |
| Enrolment: | 1,670 pupils |
| Gender: | Coeducational |
| Lower Age: | 11 |
| Upper Age: | 18 |
| Website: | https://www.stmaryschs.org.uk/ |
St Mary's Catholic High School is a Roman Catholic secondary school located in Astley, in the Metropolitan Borough of Wigan, Greater Manchester, England.[1] It is a large school hosting approximately 1,700 pupils including a sixth form.