| SMACKOVER OIL FIELD CHEMICALS, INC. | — | 207143 | 1981-05-18 | Dissolved | HATTIESBURG |
| SMALLWOOD AUTO SALES, INCORPORATED | — | 207151 | 1981-07-03 | Dissolved | |
| SMC ACQUISITION CO., INC. | — | 239146 | 1981-07-01 | | Gulfport |
| SMC ENTERPRISES, INC. | — | 205014 | 1981-01-12 | Dissolved | |
| SMCI INCORPORATED | — | 510419 | 1981-07-01 | Merged | Gulfport |
| SMF MANAGEMENT, INC. | — | 205021 | 1981-04-28 | Revoked | CORDOVA |
| SMIB ENTERPRISES, LTD. | — | 207156 | 1981-05-13 | Dissolved | |
| SMITH & BRUMLEY ATHLETIC HOUSE, INC. | — | 303204 | 1981-07-30 | Dissolved | Southaven |
| SMITH & SMITH INSURANCE AGENCY OF JACKSON, INC. | — | 502261 | 1981-12-31 | Active | JACKSON |
| SMITH GENERAL CONTRACTOR'S, INC. | Construction | 303230 | 1981-05-01 | Canceled | Gulfport |
| SMITH TIRE AND AUTO SERVICE, INC. | Wholesale trade | 303257 | 1981-03-20 | Active | LONG BEACH |
| SMITH'S PECANS, INC. | — | 303270 | 1981-03-02 | Dissolved | RAYMOND |
| SMITH, TURNER & REEVES, A PROFESSIONAL ASSOCIATION | — | 594224 | 1981-12-01 | Dissolved | JACKSON |
| SMITH-HINDSMAN INSURANCE AGENCY, INC. | Construction | 562692 | 1981-12-31 | Active | JACKSON |
| SMORGASBORD ENTERPRISES, INC. | — | 303287 | 1981-01-08 | Dissolved | Gulfport |
| SNAPPY SACKER ENTERPRISES, INC. | — | 303297 | 1981-06-11 | Dissolved | |
| SNYDER EXPLORATION COMPANY | Mining, oil and gas | 303316 | 1981-08-17 | Canceled | Gulfport |
| SOIL AND MATERIAL ENGINEERS, INC. | — | 303347 | 1981-05-27 | | Gulfport |
| SOLAR ENERGY ELECTRICAL & MECHANICAL SERVICES, INC. | — | 502965 | 1981-11-23 | Dissolved | GREENVILLE |
| SOLAR ENERGY SPECIALISTS, INC. | — | 303354 | 1981-01-23 | Dissolved | |
| SOLOMON AND PREWITT, INCORPORATED | — | 303371 | 1981-05-18 | Dissolved | |
| SOMAG, INC. | — | 303375 | 1981-01-21 | Dissolved | |
| SOMIS CORP. | — | 303384 | 1981-06-15 | Dissolved | Gulfport |
| SONICS ASSOCIATES, INC. | — | 303434 | 1981-07-07 | Revoked | Madison |
| SONNY'S ELECTRICAL & MECHANICAL SUPPLY, INC. | — | 303441 | 1981-06-02 | | |
| SONNY'S PAWN SHOP, INC. | — | 303444 | 1981-03-16 | Dissolved | |
| SORRELLS, BOWERS & COATS, INC. | — | 615487 | 1981-07-03 | Dissolved | GREENVILLE |
| SORRELLS, TERRELL & BOWERS, INC. | — | 615486 | 1981-07-03 | | |
| SOSO OILFIELD SERVICES, INC. | — | 303480 | 1981-04-14 | Dissolved | |
| SOUTH CENTRAL PEST CONTROL, INC. | — | 401684 | 1981-08-14 | Dissolved | CUTOFF PETAL |
| SOUTH DELTA INVESTMENT ASSOCIATION, INC. | — | 401710 | 1981-10-14 | Dissolved | |
| SOUTH FULTON TRAILER COURT, INC. | — | 401723 | 1981-07-27 | Dissolved | FULTON |
| SOUTH JONES CABLE COMPANY, INC. | — | 401738 | 1981-09-17 | Dissolved | |
| SOUTH MACH - 7, INC. | — | 502314 | 1981-12-02 | Dissolved | |
| SOUTH MISSISSIPPI HOME HEALTH CREDIT UNION | — | 550284 | 1981-05-28 | Merged | HATTIESBURG |
| SOUTH MISSISSIPPI LEGAL CLINIC, P.A. | — | 401791 | 1981-03-11 | | |
| SOUTH MISSISSIPPI OIL FIELD SERVICE CORPORATION | — | 401794 | 1981-01-06 | Dissolved | |
| SOUTH MISSISSIPPI OPPORTUNITIES INDUSTRIALIZATION CENTER, INC. | — | 401795 | 1981-01-23 | Active | HATTIESBURG |
| SOUTH MISSISSIPPI WELDING, INC. | — | 401809 | 1981-10-19 | Dissolved | |
| SOUTH UNION CHURCH CEMETERY ASSOCIATION OF WEBSTER COUNTY, MISSISSIPPI, INC. | — | 401843 | 1981-09-11 | Active | EUPORA |
| SOUTH-WIDE SERVICES, INC. | — | 401851 | 1981-04-13 | Dissolved | SANDY HOOK |
| SOUTHAVEN COUNTRY CLUB, INC. | — | 401857 | 1981-05-04 | Dissolved | SOUTHAVEN |
| SOUTHAVEN EMERGENCY CLINIC, INC. | — | 401858 | 1981-05-11 | Dissolved | |
| SOUTHAVEN GERIATRIC CENTER, INC. | — | 401865 | 1981-04-30 | Merged | |
| SOUTHAVEN SOUND SHOP, INC. | — | 401873 | 1981-08-25 | Dissolved | |
| SOUTHEASTERN ENERGY CORPORATION | — | 502320 | 1981-11-06 | Dissolved | |
| SOUTHEASTERN INSURANCE AGENCY, INC. | — | 401949 | 1981-07-01 | Dissolved | JACKSON |
| SOUTHEASTERN LAND SERVICES CO., INC. | — | 401952 | 1981-07-13 | Dissolved | |
| SOUTHEASTERN MICROWAVE, INC. | — | 401954 | 1981-04-22 | Dissolved | |
| SOUTHEASTERN NORM ENVIRONMENTAL, INC. | — | 597619 | 1981-08-21 | Dissolved | LAUREL |