| OMOpta Minerals | Baltimore | MD | Nonmetallic Mineral Product Manufacturing327992 | — | ◇ UNVERIFIED |
| OMOsprey Marine Composites INC | Tracys Landing | MD | Transportation Equipment Manufacturing336611 | — | ◇ UNVERIFIED |
| OBOtterbein's Bakery, INC. | Baltimore | MD | Food Manufacturing311811 | 20-99 | ◇ UNVERIFIED |
| PPace | Annapolis Junction | MD | Fabricated Metal Product Manufacturing332212 | — | ◇ UNVERIFIED |
| PCPall Ciorporation Plant 2 | Lutherville Timonium | MD | Machinery Manufacturing333412 | — | ◇ UNVERIFIED |
| PFPall Filtration & Separations Group | Timonium | MD | Machinery Manufacturing333412 | — | ◇ UNVERIFIED |
| PCPangborn CORP | Hagerstown | MD | Machinery Manufacturing333319 | — | ◇ UNVERIFIED |
| PDPeake Delancey Printers | Cheverly | MD | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| PCPemco CORP - Yard 56 | Baltimore | MD | Chemical Manufacturing325510 | — | ◇ UNVERIFIED |
| PCPepsi Cola Bottlers of Wash | Cheverly | MD | Beverage and Tobacco Product Manufacturing312111 | — | ◇ UNVERIFIED |
| PCPepsi Cola Bottling | Salisbury | MD | Beverage and Tobacco Product Manufacturing312110 | — | ◇ UNVERIFIED |
| PMPerdue Main Office Complex and Lab | Salisbury | MD | Food Manufacturing311615 | — | ◇ UNVERIFIED |
| PFP. Flanigan and Sons, INC - Annapolis Rd | Baltimore | MD | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| PPPharmaceutical Preperation Manufacturing | Hunt Valley | MD | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| PIPharmaceutics International INC. | Cockeysville | MD | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| PIPharmaceutics International, INC. | Hunt Valley | MD | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| PCPhoenix Color CORP | Hagerstown | MD | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| PIPier-sol, INC. | Baltimore | MD | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| PIPlastipak INC | Havre De Grace | MD | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| PPPolystyrene Products | Essex | MD | Plastics and Rubber Products Manufacturing326140 | — | ◇ UNVERIFIED |
| PCPq CORP. | Baltimore | MD | Chemical Manufacturing325180 | — | ◇ UNVERIFIED |
| PBPrice Brothers Company | Perryman | MD | Nonmetallic Mineral Product Manufacturing327332 | — | ◇ UNVERIFIED |
| PCPrinting CORP of America | Timonium | MD | Printing and Related Support Activities323110 | — | ◇ UNVERIFIED |
| PIProlist INC | Frederick | MD | Printing and Related Support Activities323111 | — | ◇ UNVERIFIED |
| QAQuad Avenue Chemical & Biofuels Site | Baltimore | MD | Computer and Electronic Product Manufacturing334418 | — | ◇ UNVERIFIED |
 Quantum Technology Enterprises INC T a Pallet Guy | Denton | MD | Wood Product Manufacturing321920 | — | ◇ UNVERIFIED |
| RIRailplan International | Baltimore | MD | Transportation Equipment Manufacturing336510 | 100-499 | ◇ UNVERIFIED |
| RSRed Star Yeast | Baltimore | MD | Food Manufacturing311942 | — | ◇ UNVERIFIED |
| RIRegenxbio, INC. | Rockville | MD | Chemical Manufacturing325414 | — | ◇ UNVERIFIED |
| RURegina USA INC | Cambridge | MD | Fabricated Metal Product Manufacturing332618 | — | ◇ UNVERIFIED |
| RCReichhold Chem INC. | Baltimore | MD | Chemical Manufacturing325211 | — | ◇ UNVERIFIED |
| RBRockland Bleach & Dye Works | Baltimore | MD | Textile Mills313210 | — | ◇ UNVERIFIED |
| RPRockwood Pigments N a INC | Beltsville | MD | Chemical Manufacturing325130 | — | ◇ UNVERIFIED |
| RDRpg Diffuser Systems | Upper Marlboro | MD | Computer and Electronic Product Manufacturing334220 | — | ◇ UNVERIFIED |
| SSSafety-kleen Service Center | Silver Spring | MD | Petroleum and Coal Products Manufacturing324191 | — | ◇ UNVERIFIED |
| SSSafeway Stores - Bread Plant | Landover | MD | Food Manufacturing311812 | — | ◇ UNVERIFIED |
| SCSasol Chemicals (usa) LLC | Baltimore | MD | Chemical Manufacturing325110 | — | ◇ UNVERIFIED |
| SMSchlumberger Malco | Owings Mills | MD | Printing and Related Support Activities323113 | — | ◇ UNVERIFIED |
| SSSchultz & Sons Salvage INC | Denton | MD | Primary Metal Manufacturing331110 | — | ◇ UNVERIFIED |
| SDSchuster, Daniel, INC. | Owings Mills | MD | Nonmetallic Mineral Product Manufacturing327320 | — | ◇ UNVERIFIED |
| SISeegene, INC. | Rockville | MD | Chemical Manufacturing325414 | — | ◇ UNVERIFIED |
| SGS& G Concrete | Finksburg | MD | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| SWSherwin Williams Cleaning Solutions | Havre De Grace | MD | Chemical Manufacturing325320 | — | ◇ UNVERIFIED |
| SCSherwin-williams Crisfield | Crisfield | MD | Miscellaneous Manufacturing339994 | — | ◇ UNVERIFIED |
| SUShire U.s. Manufacturing | Owings Mills | MD | Chemical Manufacturing325412 | — | ◇ UNVERIFIED |
| SHShore Holdings INC Dba Choptank Engines | Cambridge | MD | Transportation Equipment Manufacturing336310 | — | ◇ UNVERIFIED |
| SPShowell Processing Plant | Showell | MD | Food Manufacturing311615 | — | ◇ UNVERIFIED |
| SESignode Eastern Operations | Baltimore | MD | Plastics and Rubber Products Manufacturing326112 | — | ◇ UNVERIFIED |
| SISimkins Ind. INC. | Catonsville | MD | Paper Manufacturing322220 | — | ◇ UNVERIFIED |
| SLSmith Lithograph | Rockville | MD | Food Manufacturing311920 | — | ◇ UNVERIFIED |
