| South Carolina Methodist Conference Credit Union | South Carolina |
| South Carolina National Guard Federal Credit Union | South Carolina |
| South Central Bank | Kentucky |
| South Central Bank | Illinois |
| South Central Credit Union | Michigan |
| South Central Missouri Credit Union | Missouri |
| South Central State Bank | Nebraska |
| South Charleston Employees Federal Credit Union | West Virginia |
| South Coast Bank & Trust | Georgia |
| SouthCoast Community Bank | South Carolina |
| Southcoast Health System Federal Credit Union | Massachusetts |
| South Coast ILWU Federal Credit Union | Oregon |
| South Community Credit Union | Missouri |
| South County Bank | California |
| Southcrest Bank | Georgia |
| South Division Credit Union | Illinois |
| SouthEast Bank | Tennessee |
| Southeastern Arizona Federal Credit Union | Arizona |
| Southeastern Bank | Georgia |
| Southeastern Federal Credit Union | Georgia |
| Southeast Federal Credit Union | Georgia |
| Southeast Financial Credit Union | Tennessee |
| Southeast First National Bank | Georgia |
| Southeast Michigan State Employees Federal Credit Union | Michigan |
| Southeast Missouri Community Credit Union | Missouri |
| Southeast National Bank | Iowa |
| Southeast Texas Employees Federal Credit Union | Texas |
| Southern Bancorp Bank | Arkansas |
| Southern Bank | North Carolina |
| Southern Bank | Georgia |
| Southern Bank | Missouri |
| Southern Bank of Tennessee | Tennessee |
| Southern Bank & Trust | Georgia |
| Southern Baptist Church of New York Federal Credit Union | New York |
| Southern Chautauqua Federal Credit Union | New York |
| Southern Community Bank | Tennessee |
| Southern Credit Union | Tennessee |
| Southern Federal Credit Union | Texas |
| Southern First Bank | South Carolina |
| Southern Gas Federal Credit Union | Arkansas |
| Southern Heritage Bank | Louisiana |
| Southern Heritage Bank | Tennessee |
| Southern Hills Community Bank | Ohio |
| Southern Illinois Bank | Illinois |
| Southern Independent Bank | Alabama |
| Southern Lakes Credit Union | Wisconsin |
| Southern Mass Credit Union | Massachusetts |
| Southern Michigan Bank & Trust | Michigan |
| Southern Middlesex County Teachers Federal Credit Union | New Jersey |
| Southern Mississippi Federal Credit Union | Mississippi |
| Southern Missouri Bank of Marshfield | Missouri |
| Southernmost Federal Credit Union | Florida |
| Southern Pine Credit Union | Georgia |
| Southern Security Federal Credit Union | Tennessee |
| Southern Select Community Credit Union | North Carolina |
| Southern Star Credit Union | Texas |
| Southern States Bank | Alabama |
| Southern Teachers & Parents Federal Credit Union | Louisiana |
| SouthernTrust Bank | Illinois |
| SouthFirst Bank | Alabama |
| South Florida Educational Federal Credit Union | Florida |
| South Florida Federal Credit Union | Florida |
| South Georgia Bank | Georgia |
| South Georgia Banking Company | Georgia |
| South Hills Healthcare Federal Credit Union | Pennsylvania |
| South Jennings Catholic Federal Credit Union | Louisiana |
| South Jersey Federal Credit Union | New Jersey |
| South Jersey Gas Employees Federal Credit Union | New Jersey |
| South Lafourche Bank & Trust Company | Louisiana |
| Southland Credit Union | California |
| Southland Federal Credit Union | Texas |
| Southland Savings Federal Credit Union | California |
| South Louisiana Bank | Louisiana |
| South Louisiana Highway Federal Credit Union | Louisiana |
| South Metro Federal Credit Union | Minnesota |
| South Ottumwa Savings Bank | Iowa |
| SouthPoint Bank | Alabama |
| Southpointe Credit Union | Missouri |
| Southpoint Federal Credit Union | Minnesota |
| Southport Bank | Wisconsin |
| South Porte Bank | Illinois |
| South San Francisco City Employees Federal Credit Union | California |
| South Sanpete Credit Union | Utah |
| South Shop Federal Credit Union | Illinois |
| South Shore Bank | Massachusetts |
| Southshore Credit Union | Wisconsin |
| South Shore Railroad Employees Federal Credit Union | Indiana |
| Southside Bank | Texas |
| South Side Community Federal Credit Union | Illinois |
| South Side Trust & Savings Bank of Peoria | Illinois |
| South Sound Bank | Washington |
| SouthStar Bank | Texas |
| South State Bank | South Carolina |
| South Story Bank & Trust | Iowa |
| South Texas Area Resources Credit Union | Texas |
| South Texas Federal Credit Union | Texas |
| South Texas Regional Federal Credit Union | Texas |
| South Towns Community Federal Credit Union | New York |
| SouthTrust Bank | Texas |
| Southwest 66 Credit Union | Texas |