| Kathleen Senior High School | |
| Motto: | "Go Big Red" |
| Streetaddress: | 1100 Red Devil Way |
| City: | Lakeland |
| County: | Polk County |
| State: | Florida |
| Zipcode: | 33805 |
| Country: | United States |
| Pushpin Map: | Florida#USA |
| Schooltype: | Public school |
| Established: | 1928 |
| District: | Polk County Public Schools |
| Principal: | Daraford Jones (2020 - Present) |
| Teaching Staff: | 92.00 (FTE) |
| Ratio: | 22.29 |
| Mascot: | Red Devil |
| Website: | https://khs.polkschoolsfl.com/ |
| Enrollment: | 2,051[1] |
| Enrollment As Of: | 2022-2023 |
| Colors: | Red, white and black |
| Accreditations: | Southern Association of Colleges and Schools |
Kathleen Senior High School is the second oldest of four high schools in Lakeland, Florida, United States. It was originally housed north of its present location, at the site of the current Kathleen Middle School.[2]