| Stamford Symphony OrchestraEIN 06-6100039 | Arts, Culture, Humanities | CT | $1,439,725Small | 80.32 |
| Stan Hywet Hall & GardensEIN 34-0819149 | Arts, Culture, Humanities | OH | $5,263,087Mid-sized | 73.90 |
| Stand for Children Leadership CenterEIN 52-1957214 | Education | OR | $15,543,445Large | 90.22 |
| Stand.earthEIN 94-3331587 | Environment | CA | $3,081,289Small | 88.89 |
| StandUp for KidsEIN 33-0414855 | Human Services | GA | $1,220,228Small | 92.02 |
| StandWithUsEIN 01-0566033 | International | CA | $12,583,673Mid-sized | 95.47 |
| Stanley M. Isaacs Neighborhood CenterEIN 13-2572034 | Human Services | NY | $7,899,036Mid-sized | 86.21 |
| Star of Hope MissionEIN 74-1152599 | Human Services | TX | $29,007,530Large | 86.35 |
| Starkey Hearing FoundationEIN 36-3297852 | Human Services | MN | $21,659,389Large | 92.82 |
| Starlight Children's FoundationEIN 95-3802159 | Health | CA | $9,806,057Mid-sized | 93.94 |
| STARSEIN 62-1285699 | Human Services | TN | $3,850,505Mid-sized | 91.27 |
| State Policy NetworkEIN 57-0952531 | Research and Public Policy | VA | $12,797,260Mid-sized | 88.07 |
| State Street BalletEIN 86-0717486 | Arts, Culture, Humanities | CA | $1,295,799Small | 80.63 |
| State University College at Oneonta Foundation CorporationEIN 22-2403203 | Education | NY | $3,696,700Mid-sized | 92.96 |
| State VoicesEIN 20-1115618 | Human and Civil Rights | DC | $13,763,270Large | 94.07 |
| Staten Island Economic Development Corporation (SIEDC)EIN 13-3706442 | Community Development | NY | $1,787,552Small | 86.03 |
| Statue of Liberty-Ellis Island FoundationEIN 13-3118415 | Arts, Culture, Humanities | NY | $18,817,780Large | 92.24 |
| Steadman Philippon Research InstituteEIN 88-0245022 | Health | CO | $10,428,427Mid-sized | 86.07 |
| STEPEIN 51-0188692 | Human Services | MN | $2,169,879Small | 93.36 |
| Step UpEIN 95-4701468 | Human Services | CA | $4,222,065Mid-sized | 95.14 |
| Step Up For StudentsEIN 59-3649371 | Education | FL | $674,603,917Large | 96.66 |
| Stephen CenterEIN 36-3363994 | Human Services | NE | $3,889,802Mid-sized | 89.24 |
| Stephen Siller Tunnel to Towers FoundationEIN 02-0554654 | Human Services | NY | $16,641,583Large | 98.23 |
| Stephen's Children FoundationEIN 58-2219199 | International | MI | $1,332,560Small | 71.83 |
| Stephens Family YMCAEIN 37-0673564 | Human Services | IL | $5,276,013Mid-sized | 86.80 |
| SteppingStone TheatreEIN 36-3557115 | Education | MN | $871,063Small | 79.18 |
| Stern Grove Festival AssociationEIN 94-6064356 | Arts, Culture, Humanities | CA | $2,645,452Small | 80.95 |
| Stevens-Swan Humane Society of Oneida CountyEIN 15-0551485 | Animals | NY | $1,087,872Small | 77.21 |
| Stewpot Community ServicesEIN 64-0655566 | Human Services | MS | $2,160,764Small | 91.15 |
| Still Creek RanchEIN 74-2614076 | Human Services | TX | $2,387,828Small | 67.40 |
| Stony Brook Millstone Watershed Association EIN 21-0649717 | Environment | NJ | $2,183,497Small | 91.01 |
| Storefront Academy HarlemEIN 13-2940671 | Education | NY | $3,785,092Mid-sized | 79.48 |
| Storm King Art CenterEIN 14-1457573 | Arts, Culture, Humanities | NY | $8,396,023Mid-sized | 89.00 |
| StoryCorpsEIN 13-3753011 | Arts, Culture, Humanities | NY | $10,638,243Mid-sized | 94.93 |
| Storyteller Children's CenterEIN 77-0283072 | Human Services | CA | $1,611,343Small | 91.38 |
| Straight Ahead MinistriesEIN 04-3103694 | Human Services | MA | $2,008,144Small | 85.29 |
| Strategic Resource GroupEIN 33-0780945 | Religion | MD | $17,558,750Large | 83.56 |
| StrathmoreEIN 52-1233092 | Arts, Culture, Humanities | MD | $12,121,219Mid-sized | 90.00 |
| Strawbery Banke MuseumEIN 02-0260158 | Arts, Culture, Humanities | NH | $3,204,942Small | 93.92 |
| Streams MinistriesEIN 74-2703460 | Religion | TX | $1,018,510Small | 60.02 |
| Street Law, Inc.EIN 52-2015256 | Education | MD | $1,726,408Small | 85.34 |
| Street SchoolEIN 73-0942963 | Education | OK | $2,022,478Small | 97.66 |
| Streets MinistriesEIN 62-1763815 | Human Services | TN | $2,137,688Small | 92.33 |
| Strings Music FestivalEIN 84-1101995 | Arts, Culture, Humanities | CO | $2,051,356Small | 89.13 |
| STRIVEEIN 13-3255679 | Human Services | NY | $6,254,660Mid-sized | 88.95 |
| Strong City BaltimoreEIN 52-0897806 | Human Services | MD | $11,112,362Mid-sized | 90.71 |
| Stroud Water Research CenterEIN 52-2081073 | Environment | PA | $9,504,082Mid-sized | 91.98 |
| Student Conservation Association EIN 91-0880684 | Environment | VA | $43,289,688Large | 89.65 |
| Student Leadership NetworkEIN 06-1517218 | Education | NY | $9,472,942Mid-sized | 92.02 |
| Student MobilizationEIN 71-0629392 | Religion | AR | $13,955,451Large | 83.56 |
| Student Sponsor PartnersEIN 13-3392965 | Education | NY | $7,283,038Mid-sized | 91.46 |
| Students InternationalEIN 77-0410440 | Religion | CA | $4,549,657Mid-sized | 88.40 |
| Students Rising AboveEIN 81-0615887 | Education | CA | $4,271,682Mid-sized | 90.42 |
| Students Run LAEIN 95-4430502 | Human Services | CA | $2,637,828Small | 97.10 |
| Studio in a SchoolEIN 13-3003112 | Education | NY | $6,718,983Mid-sized | 88.27 |
| Studio Museum in HarlemEIN 13-2590805 | Arts, Culture, Humanities | NY | $7,761,083Mid-sized | 88.58 |
| Suffolk County Police Athletic LeagueEIN 23-7356002 | Human Services | NY | $1,095,091Small | 76.76 |
| Sulzbacher CenterEIN 59-3229898 | Human Services | FL | $14,566,080Large | 92.02 |
| Summer Camp Opportunities Promote Education (SCOPE)EIN 20-2772242 | Education | NY | $713,151Small | 72.80 |
| Summer SearchEIN 68-0200138 | Education | CA | $18,984,959Large | 79.19 |