| New York Public RadioEIN 13-3015230 | Arts, Culture, Humanities | NY | $88,126,380Large | 91.90 |
| New York Road RunnersEIN 13-2949483 | Human Services | NY | $88,751,028Large | 90.80 |
| New York Women's FoundationEIN 13-3457287 | Human and Civil Rights | NY | $13,855,149Large | 91.73 |
| Newark MuseumEIN 22-1487275 | Arts, Culture, Humanities | NJ | $20,015,203Large | 90.13 |
| NewfieldsEIN 35-0867955 | Arts, Culture, Humanities | IN | $34,342,347Large | 82.24 |
| North Carolina Agricultural FoundationEIN 56-6049304 | Education | NC | $15,156,777Large | 94.73 |
| North Carolina Community FoundationEIN 58-1661700 | Community Development | NC | $13,930,478Large | 91.07 |
| North Carolina Museum of Art FoundationEIN 23-7071511 | Arts, Culture, Humanities | NC | $14,467,906Large | 89.83 |
| North Shore Animal League AmericaEIN 11-1666852 | Animals | NY | $41,531,218Large | 83.38 |
| North Texas Community FoundationEIN 75-2267767 | Community Development | TX | $34,160,226Large | 98.23 |
| North Texas Food BankEIN 75-1785357 | Human Services | TX | $123,735,503Large | 96.66 |
| Northeast Iowa Food BankEIN 42-1169648 | Human Services | IA | $14,934,103Large | 97.17 |
| Northern Illinois Food BankEIN 36-3203648 | Human Services | IL | $131,976,826Large | 91.81 |
| Northwest Arkansas Food BankEIN 71-0680830 | Human Services | AR | $19,790,770Large | 83.35 |
| Northwest HarvestEIN 91-0826037 | Human Services | WA | $52,945,419Large | 91.11 |
| NPH USAEIN 65-1229309 | Human Services | IL | $18,458,495Large | 87.23 |
| NPREIN 52-0907625 | Arts, Culture, Humanities | DC | $222,910,067Large | 84.25 |
| Nurse-Family PartnershipEIN 20-0234163 | Human Services | CO | $19,101,215Large | 95.10 |
| Oakland ZooEIN 94-1687847 | Animals | CA | $17,255,821Large | 90.19 |
| Ocean ConservancyEIN 23-7245152 | Environment | DC | $23,984,534Large | 91.97 |
| OceanaEIN 51-0401308 | Environment | DC | $37,880,581Large | 94.11 |
| Oklahoma Medical Research FoundationEIN 73-0580274 | Health | OK | $75,113,337Large | 93.94 |
| Old Globe TheatreEIN 95-1543396 | Arts, Culture, Humanities | CA | $25,227,945Large | 90.59 |
| Ole Miss Athletics FoundationEIN 64-0474850 | Education | MS | $41,714,200Large | 93.73 |
| Omaha Performing ArtsEIN 47-0832480 | Arts, Culture, Humanities | NE | $18,775,491Large | 85.12 |
| Omaha's Henry Doorly ZooEIN 47-0469782 | Animals | NE | $46,482,503Large | 87.05 |
| One Acre FundEIN 20-3668110 | International | IL | $98,006,834Large | 90.19 |
| One Child MattersEIN 84-1087689 | International | CO | $16,670,568Large | 85.81 |
| OneSightEIN 31-1385607 | International | OH | $19,899,787Large | 92.61 |
| Open Door Mission, OmahaEIN 47-0411375 | Human Services | NE | $29,651,669Large | 89.84 |
| Open Doors USAEIN 23-7275342 | Religion | CA | $23,492,166Large | 87.35 |
| Opera Company of PhiladelphiaEIN 23-1504706 | Arts, Culture, Humanities | PA | $14,101,013Large | 78.76 |
| Operation Blessing InternationalEIN 54-1382657 | International | VA | $272,605,727Large | 82.43 |
| Operation Food SearchEIN 43-1241854 | Human Services | MO | $33,636,061Large | 94.03 |
| Operation HomefrontEIN 32-0033325 | Human Services | TX | $48,352,893Large | 89.18 |
| Operation HOPEEIN 95-4378084 | Education | CA | $15,027,756Large | 87.82 |
| Opportunity Fund Community Development EIN 31-1719434 | Community Development | CA | $19,078,312Large | 91.49 |
| Orange County Community FoundationEIN 33-0378778 | Community Development | CA | $64,365,979Large | 94.37 |
| Orange County Rescue MissionEIN 95-2479552 | Human Services | CA | $16,241,092Large | 91.21 |
| Orange County United WayEIN 33-0047994 | Community Development | CA | $17,947,341Large | 89.73 |
| Orbis InternationalEIN 23-7297651 | International | NY | $209,113,219Large | 95.47 |
| Ordway Center for the Performing ArtsEIN 41-1428998 | Arts, Culture, Humanities | MN | $21,131,100Large | 91.33 |
| Oregon Food BankEIN 93-0785786 | Human Services | OR | $67,194,439Large | 90.96 |
| Oregon Health & Science University FoundationEIN 23-7083114 | Education | OR | $130,218,507Large | 91.70 |
| Oregon Humane SocietyEIN 93-0386880 | Animals | OR | $14,537,262Large | 92.77 |
| Oregon Museum of Science and IndustryEIN 93-0402877 | Arts, Culture, Humanities | OR | $21,468,218Large | 92.80 |
| Oregon Public BroadcastingEIN 93-0814638 | Arts, Culture, Humanities | OR | $31,776,224Large | 90.24 |
| Oregon Shakespeare FestivalEIN 93-0407022 | Arts, Culture, Humanities | OR | $41,256,313Large | 87.08 |
| Oregon SymphonyEIN 93-0446527 | Arts, Culture, Humanities | OR | $18,547,539Large | 89.51 |
| Orphan Grain TrainEIN 31-1614650 | International | NE | $49,465,762Large | 97.17 |
| ORT AmericaEIN 13-5562424 | Education | NY | $15,138,099Large | 90.27 |
| Ounce of Prevention FundEIN 36-3186328 | Human Services | IL | $56,161,326Large | 90.76 |
| Our Daily Bread MinistriesEIN 38-1613981 | Religion | MI | $46,676,641Large | 89.50 |
| Oxfam AmericaEIN 23-7069110 | International | MA | $91,570,741Large | 83.65 |
| Ozarks Food HarvestEIN 43-1426384 | Human Services | MO | $30,424,252Large | 97.46 |
| Pacific Northwest BalletEIN 91-0897129 | Arts, Culture, Humanities | WA | $25,339,726Large | 90.05 |
| Pacific Science CenterEIN 91-0750867 | Arts, Culture, Humanities | WA | $27,525,639Large | 90.48 |
| Pacific SymphonyEIN 95-3635496 | Arts, Culture, Humanities | CA | $20,980,482Large | 82.32 |
| Pancreatic Cancer Action NetworkEIN 33-0841281 | Health | CA | $32,108,869Large | 93.02 |
| Paralyzed Veterans of AmericaEIN 13-1946868 | Human and Civil Rights | DC | $105,443,694Large | 72.57 |