| 661 | One Concept Pte. Ltd. 201615793N | Active |
| 662 | Otaka Engineering And Supplies Pte. Ltd. 200511610K | Active |
| 663 | One Stop Concept Pte. Ltd. 200511052R | Active |
| 664 | Ota Tunneling Pte. Ltd. 200510674N | Active |
| 665 | Osg Containers And Modular Pte. Ltd. 200607657C | Active |
| 666 | Octopus Design & Consultant Pte. Ltd. 200516794M | Active |
| 667 | Orion Integrated Services Pte. Ltd. 200809511K | Active |
| 668 | Oswald & Son (singapore) Co. Pte. Ltd. 200720037N | Active |
| 669 | Omx2005 Technology Pte. Ltd. 200706858H | Active |
| 670 | Operating Elements Pte. Ltd. 200707340M | Active |
| 671 | One Connect International Pte. Ltd. 200305456W | Active |
| 672 | Otto Build (s) Pte Ltd 199704982H | Active |
| 673 | One Net Communications Pte. Ltd. 200302791H | Active |
| 674 | Oase Asia Pacific Pte Ltd 200006998H | Active |
| 675 | Okayi Metals Pte. Ltd. 200618395C | Active |
| 676 | Otter Design Pte Ltd 199906319H | Active |
| 677 | Orient Trackworks Company Pte Ltd 200005052E | Active |
| 678 | Oh Heng Huat Pte Ltd 200101906N | Active |
| 679 | Overmark Development Pte. Ltd. 200407792E | Active |
| 680 | Onesystems Technologies Pte. Ltd. 200504143Z | Active |
| 681 | Orchid Floras Pte Ltd 199803748C | Active |
| 682 | Octogon Construction Pte. Ltd. 200503521N | Active |
| 683 | O Liner Technology Pte Ltd 199902653M | Active |
| 684 | Oneness Engineering Pte. Ltd. 200514102R | Active |
| 685 | Ocean Tech Engineering Pte Ltd 199901860E | Active |
| 686 | Omni Engineering & Trading Pte Ltd 199903194W | Active |
| 687 | Os Builders Pte Ltd 200010159M | Active |
| 688 | Oung Construction (s) Pte Ltd 199504483Z | Active |
| 689 | Oxley Construction Pte Ltd 199503273C | Active |
| 690 | Octagon System Furniture Pte Ltd 199508015Z | Active |