The Integrated Crisis Management Centre (CIGC) says the new case was imported and brings the national total to 24, with one patient fully recovered.
Dr. Sergio Lobo, a spokesperson for CIGC, also reported 20 people intercepted entering the country illegally through the Dili Port had been quarantined at a government-run site in Tibar.
Timor-Leste closed its borders on April 16 to help prevent spread of the coronavirus.
Timor-Leste also reported 503 people in compulsory confinement and 15 people in self-quarantine across the country.
Some 1534 citizens have already completed the fourteen-day quarantine period.