| Ying Kee Yeow | 4271 | Mechanical | 2007-08-16 | Elead Associates Pte. Ltd. |
| Yiong Hoi Liong | 3531 | Civil | 2000-03-21 | P & T Consultants Pte. Ltd. |
| Yip Hoi Wah | 2170 | Civil | 1985-07-19 | SSC Construction |
| Yip Mun Fai | 4279 | Electrical | 2008-01-17 | ExxonMobil Asia Pte Ltd |
| Yip Yoke Fun | 3651 | Civil | 2001-08-21 | Building and Construction Authority |
| Yiu Han Kit | 5903 | Civil | 2026-05-28 | Meinhardt (Singapore) Pte Ltd |
| Yiu San San | 5772 | Civil | 2025-05-22 | AECOM Singapore Pte. Ltd. |
| Yogeeswaran s/o Sivasithamparam | 2881 | Mechanical | 1992-12-16 | CASY Engineering Consultancy Pte. Ltd. |
| Yogesh Kumar Chhabra | 4287 | Civil | 2008-05-15 | Novaars International Pte. Ltd. |
| Yong Chee Meng Nicholas | 5432 | Electrical | 2021-11-25 | SP Group |
| Yong Cheng Hong | 5698 | Mechanical | 2024-09-26 | Arup Singapore Private Limited |
| Yong Chong Teck | 3394 | Mechanical | 1998-04-21 | Bescon Engineering Services Pte. Ltd. |
| Yong Chor Chuan | 4060 | Electrical | 2006-06-20 | Bescon Engineering Services Pte. Ltd. |
| Yong Chye Lim | 3959 | Mechanical | 2005-04-19 | SYN@PSE Engineering Services |
| Yong Deung Ming | 3982 | Civil | 2005-06-21 | JIB Specialist Consultants Pte. Ltd. |
| Yong Fen Leong | 4128 | Civil | 2007-02-23 | KTP Consultants Pte Ltd |
| Yong Haur Ming | 5282 | Electrical | 2019-12-05 | SP Mobility Pte. Ltd. |
| Yong Kiam Long | 5491 | Mechanical | 2022-11-24 | Marina Bay Sands |
| Yong Kong Kiong | 3690 | Electrical | 2002-03-19 | SP PowerGrid Limited |
| Yong Kuan Yau | 3570 | Civil | 2000-07-18 | LYL Consultants Pte. Ltd. |
| Yong Pei Han | 5083 | Chemical | 2018-05-17 | BP Singapore Pte Ltd |
| Yong Qian Cheng | 5887 | Civil | 2026-04-23 | KTP Consultants Pte Ltd |
| Yong Shan Chi | 1428 | Civil | 1979-12-08 | S C Yong Consultants |
| Yong Shi Nien | 5739 | Mechanical | 2025-02-27 | AECOM Singapore Pte. Ltd. |
| Yong Siew Hwa | 3517 | Mechanical | 1999-10-19 | Building and Construction Authority |
| Yong Siew Onn | 3845 | Mechanical | 2003-09-16 | DP Sustainable Design Pte Ltd |
| Yong Wee Loke | 3458 | Civil | 1999-04-20 | AECOM Singapore Pte. Ltd. |
| Yong Wei Leong | 3782 | Mechanical | 2003-01-27 | Binnies Singapore Pte. Ltd. |
| Yong Yeen San Raymond | 3860 | Civil | 2003-11-18 | CMP Consultants Private Limited |
| Yoon Kok Thean | 2695 | Electrical | 1991-07-17 | Aspectus Engineering Services Pte. Ltd. |