| St. John's High School | |
| Streetaddress: | 515 East Second Street |
| City: | Delphos |
| State: | Ohio |
| County: | (Allen County) |
| Zipcode: | 45833-1708 |
| Country: | USA |
| Coordinates: | 40.8433°N -84.3342°W |
| Religion: | Roman Catholic |
| Superintendent: | Fr. Dennis Walsh |
| Principal: | Adam Lee |
| Average Class Size: | 12 to 1 |
| Type: | Private, Coeducational |
| Grades: | 7-12 |
| Athletics Conference: | Midwest Athletic Conference |
| Slogan: | A Tradition Worth Keeping Faith * Tradition * Excellence |
| Team Name: | Blue Jays |
| Yearbook: | St. John's Crest |
| Homepage: | http://www.delphosstjohns.org |
St. John's High School is a Roman Catholic private high school located in Delphos, Ohio, United States. It is located in Allen County, and is part of the Roman Catholic Diocese of Toledo. The school's mascot is the Blue Jay. The school is associated with the Midwest Athletic Conference for sports.