| RCRockwell Collins Flight Control & Information Systems | Irvine | CA | Transportation Equipment Manufacturing336413 | — | ◇ UNVERIFIED |
| RRoka | Irvine | CA | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
| RRoka | Irvine | CA | Furniture and Related Product Manufacturing337127 | — | ◇ UNVERIFIED |
| RCRoyalty Carpet Mills INC | Irvine | CA | Textile Product Mills314110 | — | ◇ UNVERIFIED |
| RLRtth, LLC | Irvine | CA | Electrical Equipment, Appliance & Component Manufacturing335999 | — | ◇ UNVERIFIED |
| SASafety and Test Facility | Irvine | CA | Transportation Equipment Manufacturing336414 | — | ◇ UNVERIFIED |
| SCSand Canyon Business Center | Irvine | CA | Machinery Manufacturing333921 | — | ◇ UNVERIFIED |
| SDSan Diego Shutter CO INC | Irvine | CA | Wood Product Manufacturing321918 | — | ◇ UNVERIFIED |
 Sandisk Technologies INC | Irvine | CA | Computer and Electronic Product Manufacturing334112 | — | ◇ UNVERIFIED |
| SHSc Health Labs LLC | Irvine | CA | Computer and Electronic Product Manufacturing334516 | — | ◇ UNVERIFIED |
| SMSd Medical System INC | Irvine | CA | Chemical Manufacturing325413 | — | ◇ UNVERIFIED |
| SSdp | Irvine | CA | Chemical Manufacturing325510 | — | ◇ UNVERIFIED |
| SPSea Pointe Construction and Development, INC. | Irvine | CA | Furniture and Related Product Manufacturing337110 | — | ◇ UNVERIFIED |
| SSSecond Source | Irvine | CA | Furniture and Related Product Manufacturing337214 | — | ◇ UNVERIFIED |
| SGS & G Creative | Irvine | CA | Printing and Related Support Activities323113 | — | ◇ UNVERIFIED |
| SAShelly Associates INC | Irvine | CA | Computer and Electronic Product Manufacturing334419 | — | ◇ UNVERIFIED |
| SOShield of Glory, INC. | Irvine | CA | Paper Manufacturing322211 | — | ◇ UNVERIFIED |
| SShiley | Irvine | CA | Computer and Electronic Product Manufacturing334510 | — | ◇ UNVERIFIED |
| SIShiley INC | Irvine | CA | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SAShimano American | Irvine | CA | Miscellaneous Manufacturing339920 | — | ◇ UNVERIFIED |
| SNSivax North America INC | Irvine | CA | Transportation Equipment Manufacturing336110 | — | ◇ UNVERIFIED |
| SSSkyworks Solutions INC | Irvine | CA | Computer and Electronic Product Manufacturing334413 | — | ◇ UNVERIFIED |
| SNSmith & Nephew Dba Arthrocare CORP | Irvine | CA | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| SCSouth County Air Services INC. | Irvine | CA | Machinery Manufacturing333415 | — | ◇ UNVERIFIED |
| SISouthern Implants INC Dba Kestone Dental | Irvine | CA | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
| SBSpectrum Business Forms INC | Irvine | CA | Printing and Related Support Activities323116 | — | ◇ UNVERIFIED |
| SOSp One, LLC | Irvine | CA | Miscellaneous Manufacturing339999 | — | ◇ UNVERIFIED |
| SJSt. Jude Medical, INC. | Irvine | CA | Computer and Electronic Product Manufacturing334517 | — | ◇ UNVERIFIED |
| SUStoredot US INC | Irvine | CA | Electrical Equipment, Appliance & Component Manufacturing335910 | — | ◇ UNVERIFIED |
| SCSully-miller Contracting CO | Irvine | CA | Petroleum and Coal Products Manufacturing324121 | — | ◇ UNVERIFIED |
| SISuntrek Industries INC | Irvine | CA | Machinery Manufacturing333414 | — | ◇ UNVERIFIED |
| SGSusan Gole | Irvine | CA | Food Manufacturing311811 | — | ◇ UNVERIFIED |
| SASwissqprint America | Irvine | CA | Machinery Manufacturing333248 | — | ◇ UNVERIFIED |
| SSynaptics | Irvine | CA | Computer and Electronic Product Manufacturing334413 | — | ◇ UNVERIFIED |
| TCTapmatic CORP | Irvine | CA | Petroleum and Coal Products Manufacturing324191 | — | ◇ UNVERIFIED |
| TSTara S. Kupumbati | Irvine, | CA | Miscellaneous Manufacturing339113 | — | ◇ UNVERIFIED |
| TUTechnica USA | Irvine | CA | Computer and Electronic Product Manufacturing334412 | — | ◇ UNVERIFIED |
| TSTech Spray INC | Irvine | CA | Miscellaneous Manufacturing339910 | — | ◇ UNVERIFIED |
| TITexas Instruments Irvine | Irvine | CA | Computer and Electronic Product Manufacturing334413 | — | ◇ UNVERIFIED |
| TKThe Kelvin | Irvine | CA | Machinery Manufacturing333921 | — | ◇ UNVERIFIED |
| TITherox INC | Irvine | CA | Miscellaneous Manufacturing339112 | — | ◇ UNVERIFIED |
| TSTinco Sheet Metal Contractors | Irvine | CA | Fabricated Metal Product Manufacturing332322 | — | ◇ UNVERIFIED |
| TTodds | Irvine | CA | Food Manufacturing311941 | — | ◇ UNVERIFIED |
| TRToyota Racing Development USA INC - Irvine | Irvine | CA | Transportation Equipment Manufacturing336390 | — | ◇ UNVERIFIED |
| TRToyota Racing Development USA INC - Murphy | Irvine | CA | Transportation Equipment Manufacturing336390 | — | ◇ UNVERIFIED |
| TSTri-county Sanblasting INC | Irvine | CA | Fabricated Metal Product Manufacturing332813 | — | ◇ UNVERIFIED |
| TTrimedyne | Irvine | CA | Machinery Manufacturing333999 | — | ◇ UNVERIFIED |
| TITruabutment INC | Irvine | CA | Miscellaneous Manufacturing339114 | — | ◇ UNVERIFIED |
| TITsi Incorporated | Irvine | CA | Computer and Electronic Product Manufacturing334516 | — | ◇ UNVERIFIED |
| TITunl Industries, INC | Irvine | CA | Fabricated Metal Product Manufacturing332312 | — | ◇ UNVERIFIED |
