| Clay High School | |
| Caption: | "Proud Home Of the Blue Devils" |
| Motto: | "Once a Blue Devil always a Blue Devil" |
| Established: | 1936 |
| Type: | Public |
| District: | Clay County School District |
| Grades: | 9-12 |
| Principal: | Jen Halter |
| Staff: | 82.80 (FTE) |
| Ratio: | 20.12 |
| Students: | 1,666 (2022–23)[1] |
| Athletics: | Blue Devils |
| Colors: | Blue and white [2] |
| Mascot: | Blue Devils |
| Campus Type: | Rural |
| Campus Size: | 10acres |
| Address: | 2025 FL-16 |
| Location: | Green Cove Springs, Florida, U.S. |
Clay High School is a four-year high school located in Green Cove Springs, Florida. It is a part of the Clay County School District.
As Clay High School is named after the county it is located in, Clay County, it is indirectly named for Henry Clay, Sr. Clay was a dominant figure in both the First Party System to 1824, and the Second Party System after that. Known as "The Great Compromiser" and "The Great Pacifier" for his ability to bring others to agreement, he was the founder and leader of the Whig Party and a leading advocate of programs for modernizing the economy, especially tariffs to protect industry, a national bank, and internal improvements to promote canals, ports and railroads.
Clay High School was the first high school in Clay County. Prior to the construction of other high schools in the county during the mid-20th century, Clay High School served every city in the county, including Keystone Heights, Green Cove Springs, Orange Park, Penny Farms, and all the unincorporated towns in the county.
Clay High School was located at the Green Cove Springs Junior High, but now it has been moved to a much larger building off of SR 16, about 2 miles from the original school.