No, it is illegal for foreign nationals to work in Singapore without a valid work pass. The Ministry of Manpower (MOM) enforces strict compliance under the Employment of Foreign Manpower Act. Working without authorisation can result in fines, imprisonment, or deportation for the worker, and significant penalties for employers. Short-term visit passes or tourist visas do not grant work rights. To work legally, a registered employer must apply for the appropriate work pass, such as an Employment Pass, S Pass, or Work Permit, before employment begins.