The latest victim was a 34-year-old man, Silesia regional government spokesman Krzysztof Mejer said.
Authorities gave up hope of finding any more survivors in the mangled wreckage of the hall, which collapsed during a racing pigeon event Saturday afternoon.
On Monday, officials and firefighters were deliberating whether to bring in heavy equipment to start lifting the rubble.
"They will probably also decide on whether to use dogs one more time" to check for more bodies under the wreckage, he said. Sweeps by rescue dogs from Poland and the Czech Republic found nothing Sunday.
Police experts and public prosecutors were also seeking evidence to try to determine what caused the collapse. "The site, clues, and relevant documents are being secured," Katowice police spokesman Grzegorz Wierzbiecki said.
About 500 people were in the building when its roof collapsed. The last person rescued alive was pulled out less than five hours later as temperatures plunged far below zero. About 160 people were injured.
Polish authorities said 59 of the victims had been identified by Monday afternoon. Officials have said they include at least seven foreigners: two Slovaks, two Czechs and one victim each from the Netherlands, Belgium and Germany.
Jacek Pytel, another police spokesman, said authorities had also drawn up a list of "at least 10" people reported missing, but it was unclear if they were actually at the fair. Pytel did not provide their identities.
Dirk Jespers, a 55-year-old salesman from Ghent, Belgium, was among the injured being treated in Katowice hospital.
"We were very luck to survive," Jespers, who had been selling pigeon food at the fair, Jespers told The Associated Press. "My stand was next to a pillar and a near an entrance. That's why I made it out."
Jespers, who suffered minor head and chest injuries, was waiting to hear from doctors whether he was fit enough to fly home.