| Yang Haibo | 4708 | Geotechnical Engineering | 2021-03-25 | Sentosa Development Corporation |
| Yap Shih Lim | 5091 | Geotechnical Engineering | 2023-01-26 | A-Terra Consultants Pte. Ltd. |
| Yeo Ann Cheong | 2492 | Access Platform Engineering | 2017-02-16 | TUV SUD A-Reliance Pte. Ltd. |
| Yeo Ann Cheong | 2492 | Lift and Escalator Engineering | 2017-02-16 | TUV SUD A-Reliance Pte. Ltd. |
| Yeo Hwai Nien | 4445 | Pressure Vessel Engineering | 2017-03-23 | BPV Engineering & Consultancy |
| Yeo Kheng Hock Alvin | 4226 | Crane Engineering | 2017-07-18 | AY Safety Consultancy & Inspection Services |
| Yeo Kheng Hock Alvin | 4226 | Access Platform Engineering | 2017-07-18 | AY Safety Consultancy & Inspection Services |
| Yeo Kheng Hock Alvin | 4226 | Pressure Vessel Engineering | 2017-07-18 | AY Safety Consultancy & Inspection Services |
| Yeo Kwee Ming | 3873 | Lift and Escalator Engineering | 2019-05-16 | Wistec Engineers Pte. Ltd. |
| Yeo Lily | 3600 | Geotechnical Engineering | 2007-07-19 | AGS Consultants Pte. Ltd. |
| Yeong Chark Sung | 3985 | Pressure Vessel Engineering | 2017-10-23 | AKC Engineering Inspection Services |
| Yeong Chark Sung | 3985 | Access Platform Engineering | 2017-10-23 | AKC Engineering Inspection Services |
| Yeong Chark Sung | 3985 | Lift and Escalator Engineering | 2017-10-23 | AKC Engineering Inspection Services |
| Yeong Chark Sung | 3985 | Crane Engineering | 2017-10-23 | AKC Engineering Inspection Services |
| Yeow Mei Leng | 3159 | Lift and Escalator Engineering | 2021-07-21 | Arup Singapore Private Limited |
| Yet Nai Song | 3565 | Geotechnical Engineering | 2007-07-19 | Building and Construction Authority |
| Yogeeswaran s/o Sivasithamparam | 2881 | Pressure Vessel Engineering | 2017-03-23 | CASY Engineering Consultancy Pte. Ltd. |
| Yogeeswaran s/o Sivasithamparam | 2881 | Lift and Escalator Engineering | 2019-05-16 | CASY Engineering Consultancy Pte. Ltd. |
| Yogeeswaran s/o Sivasithamparam | 2881 | Amusement Ride Engineering | 2011-02-17 | CASY Engineering Consultancy Pte. Ltd. |
| Yong Chye Lim | 3959 | Access Platform Engineering | 2017-05-22 | Syn@pse Engineering Services |
| Yong Chye Lim | 3959 | Lift and Escalator Engineering | 2017-05-22 | Syn@pse Engineering Services |
| Yong Chye Lim | 3959 | Crane Engineering | 2017-05-22 | Syn@pse Engineering Services |
| Yong Chye Lim | 3959 | Pressure Vessel Engineering | 2017-05-22 | Syn@pse Engineering Services |
| Yong Deung Ming | 3982 | Geotechnical Engineering | 2007-04-19 | JIB Specialist Consultants Pte. Ltd. |
| Yong Kuan Yau | 3570 | Tunnelling Engineering | 2022-04-28 | LYL Consultants Pte. Ltd. |
| Yuan Zhen | 4324 | Geotechnical Engineering | 2014-05-15 | AECOM Singapore Pte. Ltd. |
| Yulius Halim Gunawan | 5159 | Geotechnical Engineering | 2025-11-27 | CPG Consultants Pte Ltd |
| Zhang Bin | 4573 | Geotechnical Engineering | 2014-01-16 | Land Transport Authority (LTA) |
| Zhang Xu | 4371 | Geotechnical Engineering | 2011-11-17 | WSP Consultancy Pte. Ltd. |
| Zhang Yaodong | 4532 | Geotechnical Engineering | 2014-06-23 | Surbana Jurong Consultants Pte. Ltd. |