Italian fire service divers found the woman’s body on deck seven of the vessel, about 10 m below the water line, Italy’s Civil Protection Authority said.
Rescue workers are still looking for 20 people who are believed to be missing.
The ship sank on 13 January after hitting rocks near the island of Giglio, off Tuscany.
Only eight of the 13 bodies discovered have so far been identified.
Four of the victims were French, one was Italian, one Hungarian, one Spanish and one German, officials say.
The identity of a woman whose body was found on Saturday has yet to be established, along with those of three men discovered previously.
The head of the Civil Protection Agency, Franco Gabrielli, said the woman may be a Hungarian who was reported missing but was not on the ship’s embarkation list.
There could have been more “illegals” on board, he said, referring to people who were not registered to be on the vessel.
There were known to be 4,200 people on the cruise ship when it got into trouble.
Costa Concordia captain, Francesco Schettino, is being detained under house arrest while his actions are investigated.
Francesco Schettino is accused of multiple manslaughter, causing a shipwreck, and abandoning ship before all passengers were evacuated. He denies the allegations.
Prosecutors say Francesco Schettino was sailing too close to Giglio on an unauthorised course in order to perform a “salute” – a greeting to islanders.
The Italian media have released a new recording in which Captain Francesco Schettino appears to say he will be the last to leave the ship.
In a previously released tape an official is heard repeatedly ordering him back on board.
Coastguard and navy divers have been blasting their way into submerged areas of the vessel using explosives in an effort to find those unaccounted for.
Emergency officials said on Saturday they would not end the search until the whole ship had been examined.
Work has been suspended several times due to poor weather.
More than 600 members of the Italian emergency services are working on the search operation.
One official said swift action was needed to remove the fuel. An Italian naval vessel is on standby as a precaution should there be an oil leak.
Although there has been no leak so far, the civil protection agency says there is pollution in the water from solvents and disinfectants which were on board the vessel.
Quincy Jones, the celebrated musician and producer who worked with Michael Jackson, Frank Sinatra, Ray…
Misleading allegations, rumours and outright lies about voting and fraud are flooding online spaces in…
At least 158 people have died in Spain's worst flooding disaster in generations. On October…
Google has been fined two undecillion (a two followed by 36 zeroes) roubles by a…
Embarking on a home remodel is an exciting journey, promising enhanced comfort, increased property value,…
The US presidential candidates continued to campaign across key swing states on October 20. Footage…