The Health Ministry says a 22-year-old man and a 66-year-old woman are the latest cases.
The ministry said the man had arrived in the country from Durban, South Africa, and had transited through Auckland.
He returned a positive result during routine quarantine testing while undergoing the mandatory 14-day quarantine in a government designated border quarantine facility in Nadi.
The ministry said the man currently has no symptoms, and further investigations are underway to determine whether this is a historical case of the coronavirus.
The woman had travelled from Sacramento, in the United States and returned a weak positive result during routine quarantine testing while undergoing the mandatory 14-day quarantine.
The ministry said that a weak positive indicated that a small amount of viral material was detected in the sample, which was likely a non-viable virus.
"She currently has no symptoms and is currently considered a historical case that was likely infected, and recovered, sometime before arriving in Fiji," a statement from the ministry said.
"Both individuals were transferred to the isolation ward at the Lautoka hospital in accordance with the standard protocol for Covid-19 cases.
"The frontline border quarantine staff that may have had any contact with the cases will be monitored and tested as a precaution according to our protocols."
Fiji has now had 59 cases in total, with three active cases, 54 recoveries and two deaths since the first case was reported on March 19, 2020.