| Cocoon HouseEIN 91-1497667 | Human Services | WA | $4,854,869Mid-sized | 87.51 |
| Cold Spring Harbor LaboratoryEIN 11-2013303 | Research and Public Policy | NY | $147,631,524Large | 92.80 |
| Collaborative for Academic, Social, and Emotional LearningEIN 20-5884201 | Education | IL | $6,773,512Mid-sized | 88.56 |
| College Bound, CAEIN 95-4604550 | Education | CA | $709,979Small | 68.46 |
| College Bound, MOEIN 20-4768985 | Education | MO | $2,509,817Small | 91.73 |
| College Golf FellowshipEIN 55-0798282 | Religion | CA | $2,573,949Small | 81.83 |
| College Now Greater ClevelandEIN 34-6580096 | Education | OH | $12,466,427Mid-sized | 95.47 |
| College PossibleEIN 41-1968798 | Education | MN | $16,391,039Large | 91.38 |
| College TrackEIN 94-3279613 | Education | CA | $18,429,592Large | 96.15 |
| CollegeBound FoundationEIN 52-1598921 | Education | MD | $3,336,619Small | 85.81 |
| Collision Repair Education FoundationEIN 36-3768028 | Education | IL | $11,564,561Mid-sized | 92.54 |
| Colon Cancer Coalition EIN 30-0377727 | Health | MN | $1,402,947Small | 86.69 |
| Colonial Heights Food PantryEIN 20-8932952 | Human Services | VA | $1,061,505Small | 77.42 |
| Colonial Williamsburg FoundationEIN 54-0505888 | Arts, Culture, Humanities | VA | $138,893,757Large | 84.28 |
| Colorado Center on Law and PolicyEIN 84-1264154 | Research and Public Policy | CO | $1,154,061Small | 92.33 |
| Colorado Children's CampaignEIN 74-2374672 | Human and Civil Rights | CO | $2,182,396Small | 91.93 |
| Colorado Education InitiativeEIN 26-1597530 | Education | CO | $7,489,959Mid-sized | 85.38 |
| Colorado Neurological InstituteEIN 84-1100975 | Health | CO | $2,596,095Small | 80.93 |
| Colorado Public RadioEIN 74-2324052 | Arts, Culture, Humanities | CO | $17,648,179Large | 95.44 |
| Colorado Springs Fine Arts CenterEIN 84-0406947 | Arts, Culture, Humanities | CO | $6,797,225Mid-sized | 90.71 |
| Colorado Springs Philharmonic OrchestraEIN 74-3091110 | Arts, Culture, Humanities | CO | $3,917,452Mid-sized | 85.50 |
| Colorado SymphonyEIN 84-0511458 | Arts, Culture, Humanities | CO | $13,000,490Mid-sized | 82.60 |
| Colorado UpLiftEIN 84-0889330 | Education | CO | $5,716,706Mid-sized | 87.29 |
| Colorectal Cancer AllianceEIN 86-0947831 | Health | DC | $6,452,188Mid-sized | 90.18 |
| Columbia Lighthouse for the BlindEIN 53-0196609 | Human Services | DC | $6,245,235Mid-sized | 76.66 |
| Columbia Museum of ArtEIN 57-6007869 | Arts, Culture, Humanities | SC | $4,269,010Mid-sized | 78.98 |
| Columbia/Barnard HillelEIN 23-7077182 | Religion | NY | $2,790,514Small | 75.51 |
| Columbus Citizens FoundationEIN 13-6118967 | Education | NY | $4,362,512Mid-sized | 85.20 |
| Columbus HumaneEIN 31-4379492 | Animals | OH | $2,907,190Small | 87.61 |
| Columbus Museum of ArtEIN 31-4379447 | Arts, Culture, Humanities | OH | $13,970,682Large | 91.73 |
| Columbus Symphony OrchestraEIN 31-6402408 | Arts, Culture, Humanities | OH | $8,505,883Mid-sized | 86.14 |
| Columbus Zoo and AquariumEIN 31-4390844 | Animals | OH | $71,124,051Large | 92.24 |
| Combined Jewish PhilanthropiesEIN 04-2103559 | Community Development | MA | $166,682,869Large | 94.56 |
| Comfort Zone CampEIN 54-1916517 | Health | VA | $2,096,801Small | 74.85 |
| Comic Relief Inc.EIN 01-0885377 | Human Services | NY | $91,909,090Large | 89.02 |
| Coming CleanEIN 04-3429794 | Environment | VT | $984,122Small | 82.69 |
| Coming Home Network InternationalEIN 34-1732696 | Religion | OH | $1,542,591Small | 66.54 |
| CommentaryEIN 13-3610041 | Arts, Culture, Humanities | NY | $3,059,126Small | 90.59 |
| Commission To Every NationEIN 74-2730294 | Religion | TX | $17,045,573Large | 96.46 |
| Committee For A Constructive TomorrowEIN 52-1462893 | Environment | DC | $1,754,758Small | 70.10 |
| Committee for Accuracy in Middle East Reporting in AmericaEIN 52-1332702 | International | MA | $4,796,135Mid-sized | 93.69 |
| Committee on Temporary ShelterEIN 03-0285606 | Human Services | VT | $3,566,411Mid-sized | 88.33 |
| Committee to Protect JournalistsEIN 13-3081500 | Human and Civil Rights | NY | $7,345,573Mid-sized | 92.83 |
| Common Cause Education FundEIN 31-1705370 | Human and Civil Rights | DC | $7,223,861Mid-sized | 93.96 |
| Common Counsel FoundationEIN 94-3214166 | Community Development | CA | $3,914,023Mid-sized | 85.93 |
| Common HopeEIN 41-1560297 | International | MN | $4,867,551Mid-sized | 94.76 |
| Common Sense MediaEIN 41-2024986 | Arts, Culture, Humanities | CA | $22,906,362Large | 93.91 |
| Common ThreadsEIN 20-0106847 | Human Services | TX | $3,810,395Mid-sized | 91.24 |
| CommonBond CommunitiesEIN 41-1260469 | Community Development | MN | $13,518,416Large | 92.27 |
| CommonwealEIN 94-2366094 | Health | CA | $4,034,106Mid-sized | 93.02 |
| CommonwealthEIN 04-3540147 | Community Development | MA | $1,993,340Small | 91.42 |
| Commonwealth Foundation EIN 23-2473845 | Research and Public Policy | PA | $2,993,022Small | 88.36 |
| Communications Consortium Media CenterEIN 52-1524972 | Research and Public Policy | DC | $927,021Small | 79.49 |
| Communities for a Better EnvironmentEIN 94-2998086 | Environment | CA | $2,066,472Small | 83.88 |
| Communities Foundation of TexasEIN 75-0964565 | Community Development | TX | $129,532,950Large | 91.42 |
| Communities In Schools National OfficeEIN 58-1289174 | Education | VA | $20,927,294Large | 90.78 |
| Communities in Schools of Charlotte Mecklenburg, Inc.EIN 58-1661795 | Education | NC | $6,728,143Mid-sized | 92.07 |
| Communities in Schools of ChicagoEIN 36-3591326 | Education | IL | $2,653,240Small | 91.75 |
| Communities In Schools of GeorgiaEIN 58-1912923 | Education | GA | $2,649,158Small | 85.85 |
| Communities In Schools of HoustonEIN 76-0031827 | Education | TX | $12,788,149Mid-sized | 91.61 |