| Santee Cooper Credit Union | South Carolina |
| Santo Christo Federal Credit Union | Massachusetts |
| Sarasota Municipal Employees Credit Union | Florida |
| Saratoga National Bank and Trust | New York |
| Saratoga's Community Federal Credit Union | New York |
| SARCO Federal Credit Union | Pennsylvania |
| Sargent County Bank | North Dakota |
| Sargent Federal Credit Union | District of Columbia |
| Sauk Valley Bank & Trust Company | Illinois |
| Savannah Bank | New York |
| Savannah Federal Credit Union | Georgia |
| Savannah Postal Credit Union | Georgia |
| Savannah Schools Federal Credit Union | Georgia |
| Savanna-Thomson State Bank | Illinois |
| Savastate Teachers Federal Credit Union | Georgia |
| Savers Co-operative Bank | Massachusetts |
| SaviBank | Washington |
| Savings Bank | Iowa |
| Savings Bank of Danbury | Connecticut |
| Savings Bank of Mendocino County | California |
| Savings Bank of Walpole | New Hampshire |
| Savings Institute Bank & Trust | Connecticut |
| Savoy Bank | New York |
| Sawyer Savings Bank | New York |
| Sb1 Federal Credit Union | Pennsylvania |
| S Bank | Georgia |
| SB Community Federal Credit Union | Michigan |
| SCE Federal Credit Union | California |
| Scenic Falls Federal Credit Union | Idaho |
| SCFE Credit Union | Ohio |
| SCF Westchester NY Employees Federal Credit Union | New York |
| Schaumburg Bank & Trust Company | Illinois |
| SCHD Dist #7 Federal Credit Union | South Carolina |
| Schenectady County Employees Federal Credit Union | New York |
| Schertz Bank & Trust | Texas |
| Schlumberger Employees Credit Union | Texas |
| Schneider Community Credit Union | Wisconsin |
| Schofield Federal Credit Union | Hawaii |
| School District 218 Employees Federal Credit Union | Illinois |
| School District 3 Federal Credit Union | Colorado |
| School District #9 Credit Union | Illinois |
| School Districts 162/163 Employees Federal Credit Union | Illinois |
| School Employees Credit Union | Wisconsin |
| School Employees of Washington Credit Union | Washington |
| Schools Federal Credit Union | California |
| Schools Financial Credit Union | California |
| SchoolsFirst Federal Credit Union | California |
| School Systems Federal Credit Union | New York |
| Schuyler Savings Bank | New Jersey |
| Schuylkill Federal Credit Union | Pennsylvania |
| SCICAP Credit Union | Iowa |
| Science Park Federal Credit Union | Connecticut |
| Scient Federal Credit Union | Connecticut |
| Scientific Research Partner's Credit Union | Missouri |
| SCI Federal Credit Union | South Carolina |
| Scituate Federal Savings Bank | Massachusetts |
| SC MembersFirst Federal Credit Union | South Carolina |
| Scotia Bank | Ontario |
| Scott and White Employees Credit Union | Texas |
| Scott Associates Credit Union | Ohio |
| Scott Credit Union | Illinois |
| Scottrade Bank | Missouri |
| Scottsburg Building and Loan Association | Indiana |
| Scott State Bank | Illinois |
| Scott Valley Bank | California |
| Scranton Times Downtown Federal Credit Union | Pennsylvania |
| Scribner Bank | Nebraska |
| SC State Federal Credit Union | South Carolina |
| SC Telco Federal Credit Union | South Carolina |
| Scurry County School Federal Credit Union | Texas |
| Sea Air Federal Credit Union | California |
| Seaboard Federal Credit Union | Maine |
| Seaboard Gateway Federal Credit Union | Indiana |
| Seacoast Bank | Florida |
| Seacoast Commerce Bank | California |
| SeaComm Federal Credit Union | New York |
| SEA Credit Union | Utah |
| Seagoville Federal Credit Union | Texas |
| Seamen's Bank | Massachusetts |
| Seaport Credit Union | Massachusetts |
| Seaport Federal Credit Union | New Jersey |
| Sears Spokane Employees Federal Credit Union | Washington |
| Seaside National Bank & Trust | Florida |
| Seasons Federal Credit Union | Connecticut |
| Seattle Bank | Washington |
| Seattle Metropolitan Credit Union | Washington |
| Seaway Bank and Trust Company | Illinois |
| Sea West Coast Guard Federal Credit Union | California |
| Sebasticook Valley Federal Credit Union | Maine |
| Sebree Deposit Bank | Kentucky |
| SECNY Federal Credit Union | New York |
| Second Federal Savings and Loan Association of Philadelphia | Pennsylvania |
| Section 705 Federal Credit Union | Louisiana |
| SECU Credit Union | Iowa |
| SECU Credit Union | Maryland |
| Securant Bank & Trust | Wisconsin |
| Secured Advantage Federal Credit Union | South Carolina |
| Secure First Credit Union | Alabama |
| Security Bank | Tennessee |
| Security Bank | Oklahoma |