| Southwest Airlines Federal Credit Union | Texas |
| Southwest Bank | Texas |
| Southwest Bank | Texas |
| Southwest Capital Bank | New Mexico |
| Southwest Colorado Federal Credit Union | Colorado |
| Southwest Communities Federal Credit Union | Pennsylvania |
| Southwest Counties School Employees Credit Union | Missouri |
| Southwestern National Bank | Texas |
| Southwest Federal Credit Union | New Mexico |
| Southwest Financial Federal Credit Union | Texas |
| Southwest Georgia Bank | Georgia |
| Southwest Health Care Credit Union | Arizona |
| Southwest Heritage Credit Union | Texas |
| Southwest Kansas Community Credit Union | Kansas |
| Southwest Louisiana Credit Union | Louisiana |
| Southwest Missouri Bank | Missouri |
| Southwest Montana Community Federal Credit Union | Montana |
| Southwest National Bank | Oklahoma |
| Southwest National Bank | Kansas |
| Southwest Oklahoma Federal Credit Union | Oklahoma |
| Southwest Research Center Federal Credit Union | Texas |
| Southwind Bank | Kansas |
| So-Val Tel Federal Credit Union | California |
| Sovereign Bank | Texas |
| Soy Capital Bank | Illinois |
| Space Age Federal Credit Union | Colorado |
| Space Age Tulsa Federal Credit Union | Oklahoma |
| Space City Credit Union | Texas |
| Space Coast Credit Union | Florida |
| Spartanburg City Employees Credit Union | South Carolina |
| Spartan Federal Credit Union | South Carolina |
| SPC Brooklyn Federal Credit Union | New York |
| SPC Credit Union | South Carolina |
| SPCO Credit Union | Texas |
| Special Metals Federal Credit Union | New York |
| SPE Federal Credit Union | Pennsylvania |
| SPELC Federal Credit Union | Louisiana |
| Spencer County Bank | Indiana |
| Spencerport Federal Credit Union | New York |
| Spencer Savings Bank | New Jersey |
| Spencer Savings Bank | Massachusetts |
| Sperry Associates Federal Credit Union | New York |
| Sperry Marine Federal Credit Union | Virginia |
| Spire Credit Union | Minnesota |
| SpiritBank | Oklahoma |
| Spirit of Alaska Federal Credit Union | Alaska |
| Spirit of America Federal Credit Union | Nebraska |
| Spirit of Texas Bank | Texas |
| Spiro State Bank | Oklahoma |
| Spohn Health System Federal Credit Union | Texas |
| Spojnia Credit Union | Pennsylvania |
| Spokane City Credit Union | Washington |
| Spokane Federal Credit Union | Washington |
| Spokane Firefighters Credit Union | Washington |
| Spokane Law Enforcement Credit Union | Washington |
| Spokane Media Federal Credit Union | Washington |
| Spokane Teachers Credit Union | Massachusetts |
| Spokane Teachers Credit Union | Washington |
| Spratt Savings and Loan Association | South Carolina |
| Spring Bank | New York |
| Spring Bank | Wisconsin |
| Springdale PPG Federal Credit Union | Pennsylvania |
| Springfield Catholic Credit Union | Missouri |
| Springfield City Employees Credit Union | Illinois |
| Springfield First Community Bank | Missouri |
| Springfield Postal Employees Federal Credit Union | Ohio |
| Springfield State Bank | Kentucky |
| Springfield State Bank | Nebraska |
| Springfield Street Railway Employees Credit Union | Massachusetts |
| Spring Hill State Bank | Texas |
| Spring Mill Employees Federal Credit Union | Pennsylvania |
| Springs Valley Bank & Trust Company | Indiana |
| Spring Valley Bank | Ohio |
| Spring Valley City Bank | Illinois |
| Spruance Cellophane Credit Union | Virginia |
| SP Trainmen Federal Credit Union | Texas |
| Spur Security Bank | Texas |
| Square 1 Bank | North Carolina |
| SRI Employees Federal Credit Union | Alabama |
| SRI Federal Credit Union | California |
| SRP Federal Credit Union | South Carolina |
| SRU Federal Credit Union | Pennsylvania |
| SSBBank | Michigan |
| SSB Community Bank | Ohio |
| S & S M H Employees Federal Credit Union | Pennsylvania |
| SSMOKE Federal Credit Union | Oklahoma |
| SS Peter & Paul Federal Credit Union | Pennsylvania |
| Stafford Savings Bank | Connecticut |
| Stage Employees Federal Credit Union | Nevada |
| St. Agnes Employees Credit Union | Wisconsin |
| St. Agnes Federal Credit Union | Maryland |
| Stamford Federal Credit Union | Connecticut |
| Stamford Healthcare Credit Union | Connecticut |
| Stamford Postal Employees Federal Credit Union | Connecticut |
| Standard Bank | Pennsylvania |
| Standard Bank and Trust Co. | Illinois |
| Standard Register Federal Credit Union | Ohio |
| Standard Steel Employees Federal Credit Union | Pennsylvania |
| Standing Stone Bank | Ohio |
| St. Andrew Kim Federal Credit Union | New Jersey |