| Callcott Reilly | |
| Nationality: | English |
| Birth Date: | 28 October 1828 |
| Birth Place: | Sheffield, West Riding of Yorkshire, England |
| Death Place: | Clergy House, Englefield Green, Egham, Surrey |
| Spouse: | Emma Birch (1852), Barbara Brant (1895) |
| Parents: | James Riley and Sarah Callcott |
| Children: | Charles, Frederick, Philip, Frances, Walter |
| Discipline: | Civil engineering |
| Institutions: | Institution of Civil Engineers |
| Significant Advance: | Uniform Stress in Girder Work |
| Significant Awards: | Telford Medal |
Callcott Reilly (28 October 1828 – 21 May 1900[1]) was a British civil and construction engineer. He is noted for his work on uniform stress, as illustrated by reference to bridge building, for which the Institution of Civil Engineers awarded him the Telford Medal in 1865.[2] He played a prominent role in promoting the professional education of engineers[3] and in 1871 became the first Professor of Engineering Construction[4] at the newly formed Royal Indian Engineering College (RIEC) located at Coopers Hill near Englefield Green.