In a statement, the republic's Ministry of Health (MOH) said the patient labelled as Case 15,237 has no recent travel history to affected countries or regions.
The 23-year-old female nurse at the National Centre for Infectious Diseases (NCID) reported the onset of symptoms on April 23, and subsequent test results confirmed COVID-19 infection yesterday.
Prior to hospital admission, the nurse, who is currently warded at NCID, had mostly been on medical leave and had only gone to work for a few hours, said the ministry.
Updating on the condition of patients, MOH said to date, 1,188 cases of COVID-19 infection have been discharged from hospitals or community isolation facilities, 22 are in critical condition in the intensive care unit and 14 have died.
Singapore yesterday identified five more new clusters at 11, Defu Lane 1; 106, International Road; 33, Senoko Way; 17, Shaw Road; and 182, Woodlands Industrial Park E5.
The republic's largest cluster, S11 Dormitory @ Punggol, has a total of 2,436 confirmed cases now.
As for yesterday, Singapore reported no imported cases, 11 cases in the community, and 19 Work Permit holders residing outside dormitories.
Meanwhile, about 95 per cent from yesterday's new cases of 690 involved dorm residents.
The ministry noted that 63 per cent are linked to known clusters, while the rest are pending contact tracing.
Singapore's current tally stands at 15,641 cases.