| Colorado Online Middle School | 211 | regular | middle |
| Colorado Preparatory Academy Elementary School | 933 | regular | elementary |
| Colorado Preparatory Academy High School | 823 | regular | high |
| Colorado Preparatory Academy Middle School | 681 | regular | middle |
| COLORADO RIVER COLLEGIATE ACADEMY | 190 | regular | high |
| Colorado School for the Deaf and Blind | 167 | special-ed | other |
| Colorado Skies Academy | 177 | regular | middle |
| Colorado Sports Leadership Academy | 425 | regular | other |
| Colorado Springs Charter Academy | 295 | regular | elementary |
| Colorado STEM Academy | 415 | regular | other |
| Colorado Summit Connections Academy | 1,245 | regular | other |
| Colorado Virtual Academy | 493 | regular | elementary |
| Colorado Virtual Academy High School | 773 | regular | high |
| Colorado Virtual Academy Middle School | 170 | regular | middle |
| Colorado's Finest High School of Choice | 216 | alternative | high |
| Colorow Elementary School | 194 | regular | other |
| Colquitt County High School | 1,932 | regular | high |
| Colrain Central | 94 | regular | other |
| COLSON ELEMENTARY SCHOOL | 511 | regular | other |
| Colstrip High School | 155 | regular | high |
| Colt Andrews School | 307 | regular | other |
| COLT EL | 572 | regular | other |
| Colter Elementary | 318 | regular | elementary |
| Colton Elementary School | 171 | regular | elementary |
| Colton High | 1,729 | regular | high |
| Colton High School | 161 | regular | high |
| Colton Middle | 870 | regular | middle |
| Colton Middle School | 110 | regular | middle |
| Colton School | 166 | regular | other |
| Colton Virtual Academy | 153 | regular | other |
| COLTON-PIERREPONT CENTRAL SCHOOL | 359 | regular | other |
| Coltrane-Webb Elementary | 386 | regular | elementary |
| Colts Neck High School | 1,430 | regular | high |
| Columbia 6th Grade Academy | 654 | regular | middle |
| Columbia Academy | 8 | alternative | elementary |
| COLUMBIA ACADEMY | 719 | regular | middle |
| Columbia Academy Anchor Program | 6 | alternative | middle |
| Columbia Alternative Education | 78 | alternative | other |
| Columbia Basin Technical Skills Center | 53 | vocational | high |
| Columbia Central High School | 637 | regular | other |
| Columbia Central High School | 1,401 | regular | high |
| Columbia Central School | 646 | regular | elementary |
| COLUMBIA CITY ELEMENTARY SCHOOL | 585 | regular | other |
| Columbia City High School | 1,202 | regular | high |
| Columbia City School | 214 | regular | elementary |
| Columbia Crest A-STEM Academy | 209 | regular | elementary |
| COLUMBIA ELEM. COMM. ED. CTR. | 216 | regular | other |
| Columbia Elementary | 430 | regular | elementary |
| Columbia Elementary | 464 | regular | elementary |
| Columbia Elementary | 620 | regular | elementary |