It means there are now two active cases on-island. Neither of them have any symptoms and are isolating in the community.
No one is being treated for the virus in hospital.
Five people have now been diagnosed with Covid-19 after arriving at the borders, which reopened on 3 July.
The new case comes on the same day that the Safer Travel Guidelines Review Panel concluded that the decision to reopen Jersey's borders was rushed and made for economic reasons.
In an interim report - the panel, led by St Helier Deputy Rob Ward, called for all arriving passengers to isolate in government-provided accommodation until they receive a negative coronavirus test result.
There are more details on the panel's findings and recommendations here.
332 people are now confirmed to have contracted COVID-19 here throughout the pandemic.
The trial into the Haut du Mont explosion, which killed ten residents nearly four years ago, has been told that Island Energy 'did not have systems in place to make sure what its employees were doing was safe'.
A Tunisian man, who sexually assaulted five women on the streets of St Helier, has been jailed for nine years, with deportation recommended upon the completion of his sentence.
Jurors have heard the 999 call made by Haut Du Mont resident Louisa De Almeida, reporting the smell of gas inside her flat, hours before the explosion that killed her and nine others in December 2022.
The supervising engineer of gas works that led to a fatal explosion at Haut du Mont was distracted when he attended the flats to check valves were closed, Jersey's Royal Court has been told.
A jury has heard claims the gas work undertaken in the area around Haut Du Mont on the day before a fatal explosion four years ago was rushed, based on 'guesswork', and 'sloppy'.