County secondary schools in Kenya form the third tier after national and extra-county schools respectively.
Most of Kenyan learners are absorbed by these schools.
Admission to county schools is done online by the Ministry of Education.
They are either mixed or single-sex.
Here is a list of county schools found in Kisumu County
| KNEC CODE | NAME OF THE SCHOOL | CATEGORY | TYPE | |
| 1 | 39701001 | KASAGAM SECONDARY SCHOOL | County | Mixed |
| 2 | 39701003 | DR. ALOO GUMBI SECONDARY SCHOOL | County | Mixed |
| 3 | 39713002 | AWASI PAG BOYS HIGH SCHOOL | County | Boys |
| 4 | 39713007 | KATOLO MIXED SECONDARY SCHOOL | County | Mixed |
| 5 | 39713009 | KOCHOGO HIGH SCHOOL | County | Mixed |
| 6 | 39713022 | WITHUR BOYS SECONDARY SCHOOL | County | Boys |
| 7 | 39713024 | MASOGO MIXED SECONDARY SCHOOL | County | Mixed |
| 8 | 39714102 | NDIRU MIXED SECONDARY SCHOOL | County | Mixed |
| 9 | 39714111 | ST. ALOYS RERU GIRLS SECONDARY SCHOOL | County | Girls |
| 10 | 39714113 | RIDORE ACK MIXED SECONDARY SCHOOL | County | Mixed |
| 11 | 39714126 | BISHOP ABIERO GIRLS MAGWAR SECONDARY SCHOOL | County | Girls |
| 12 | 39714132 | MAGWAR MODEL SECONDARY SCHOOL | County | Mixed |
| 13 | 39733107 | OLEMBO BOYS SECONDARY SCHOOL | County | Boys |
| 14 | 39733112 | THURGEM SECONDARY SCHOOL | County | Mixed |
| 15 | 39733308 | OUR LADY OF LOURDES BOLO GIRLS SECONDARY SCHOOL | County | Girls |
| 16 | 39734403 | MUHORONI MIXED SECONDARY SCHOOL | County | Mixed |
| 17 | 39734406 | ST. AUGUSTINE’S KANDEGE SECONDARY SCHOOL | County | Mixed |
| 18 | 39737002 | BISHOP OKOTH OJOLLA GIRLS SECONDARY SCHOOL | County | Girls |
| 19 | 39737030 | HUMA GIRLS SECONDARY SCHOOL | County | Girls |
| 20 | 39741008 | KISUMU DAY SECONDARY SCHOOL | County | Boys |
| 21 | 39741012 | LIONS HIGH SCHOOL | County | Mixed |