| Summit Academy OICEIN 41-0908458 | Education | MN | $7,997,922Mid-sized | 93.46 |
| Summit Speech SchoolEIN 22-1829502 | Education | NJ | $4,019,719Mid-sized | 75.56 |
| Sun Devil ClubEIN 86-0138459 | Education | AZ | $12,238,895Mid-sized | 82.26 |
| Suncoast Humane SocietyEIN 23-7174193 | Animals | FL | $2,251,735Small | 83.19 |
| Sundance InstituteEIN 87-0361394 | Arts, Culture, Humanities | CA | $42,985,822Large | 88.22 |
| Sunday Breakfast MissionEIN 51-0073080 | Human Services | DE | $5,615,126Mid-sized | 79.65 |
| Sunday Breakfast Rescue MissionEIN 23-1352558 | Human Services | PA | $3,017,157Small | 79.81 |
| Sunflower HouseEIN 48-0918698 | Human Services | KS | $1,483,883Small | 93.82 |
| Sunny Glen Children's HomeEIN 74-1260706 | Human Services | TX | $2,484,409Small | 88.16 |
| Sunnyvale Community ServicesEIN 94-1713897 | Human Services | CA | $7,426,109Mid-sized | 95.10 |
| Sunshine Division Portland Police DeptEIN 93-0429354 | Human Services | OR | $5,667,244Mid-sized | 90.89 |
| Sunshine FoundationEIN 23-2044056 | Health | PA | $1,149,331Small | 84.68 |
| Sunshine MinistriesEIN 43-0896665 | Human Services | MO | $1,553,900Small | 79.61 |
| Sunvalley Summer SymphonyEIN 82-0397940 | Arts, Culture, Humanities | ID | $3,471,245Small | 83.13 |
| SuperChannel WACX-TVEIN 59-1798262 | Religion | FL | $2,508,450Small | 56.43 |
| Support Center for Child AdvocatesEIN 23-2048664 | Human and Civil Rights | PA | $3,549,961Mid-sized | 91.29 |
| Support Circle Pregnancy ClinicsEIN 94-2937281 | Health | CA | $1,470,007Small | 76.06 |
| Support Our Aging ReligiousEIN 52-1485481 | Religion | DC | $2,598,741Small | 87.13 |
| Support The Enlisted Project (STEP)EIN 20-3051279 | Human Services | CA | $1,681,670Small | 94.41 |
| Supportive Housing Network of New YorkEIN 13-3755149 | Research and Public Policy | NY | $1,876,483Small | 87.00 |
| Surrey Services for SeniorsEIN 23-2610145 | Human Services | PA | $4,603,921Mid-sized | 91.37 |
| Susan B. Anthony Recovery CenterEIN 65-0583089 | Human Services | FL | $3,840,666Mid-sized | 79.43 |
| Susan G. Komen for the CureEIN 75-1835298 | Health | TX | $182,911,053Large | 80.87 |
| Susquehanna Council Boy Scouts of AmericaEIN 24-0795397 | Human Services | PA | $924,817Small | 86.77 |
| Sustainable ConservationEIN 94-3232437 | Environment | CA | $5,612,199Mid-sized | 88.59 |
| Sustainable Food CenterEIN 74-2441468 | Human Services | TX | $2,309,673Small | 91.45 |
| Sustainable Harvest InternationalEIN 43-2023182 | International | ME | $1,474,478Small | 76.24 |
| Sustainable NorthwestEIN 93-1152222 | Environment | OR | $1,715,550Small | 79.08 |
| Swiftsure Ranch Theraputic Equestrian CenterEIN 82-0461587 | Health | ID | $880,783Small | 70.49 |
| Swim Across AmericaEIN 22-3248256 | Health | NC | $6,543,494Mid-sized | 85.42 |
| Sword of the LordEIN 36-2212715 | Religion | TN | $1,122,169Small | 69.01 |
| Symphony Orchestra AugustaEIN 58-1806334 | Arts, Culture, Humanities | GA | $1,329,082Small | 71.30 |
| Symphony Silicon ValleyEIN 32-0083030 | Arts, Culture, Humanities | CA | $3,744,844Mid-sized | 83.56 |
| Symphony SpaceEIN 13-2941455 | Arts, Culture, Humanities | NY | $6,686,548Mid-sized | 91.83 |
| Symphony TacomaEIN 91-6032976 | Arts, Culture, Humanities | WA | $1,209,023Small | 77.32 |
| SynergosEIN 13-3392006 | International | NY | $14,088,067Large | 93.42 |
| Syracuse StageEIN 15-0623468 | Arts, Culture, Humanities | NY | $5,682,361Mid-sized | 84.78 |