While the inmates' lawyers said the move was political expedience, U.S. government officials said it signaled another step toward emptying the controversial prison camp, the Miami Herald reported.
The transfer Wednesday leaves the prisoner population at the U.S. Navy base at 162 men, the Herald reported.
The inmates -- Djamel Ameziane, 46, and Belkacem Bensayah, 51 -- were brought to the base separately in 2002. In January 2010, an Obama administration task force approved their transfer to a country willing to "implement appropriate security measures."
The men were not charged during their detention at the Guantanamo facility.
Their lawyers said the men opposed return to their homeland because they separately fled turmoil in Algeria in the 1990s and had been asking Western nations for safe haven.
At the U.S. State Department, the special envoy for Guantanamo closure issued a statement thanking the government of Algeria, the newspaper said.
Robert Kirsch, Bensayah's attorney, and Ameziane's attorney, Wells Dixon, said separately European countries were willing to accept men released from Guantanamo and criticized the Obama administration for their return to Algeria.
"The U.S. government has ruined Ameziane's life," Dixon said. "For 20 years he has fled violence and instability in Algeria only to be forcibly returned there by the U.S. government despite his well-documented fear of persecution."
Dixon said the transfer violated international law because Ameziane "likely faces persecution" by returning to Algeria and wasn't given a chance to argue his case before an international body.
"Mr. Bensayah has not lived in Algeria for more than 20 years," Kirsch said. "His parents are dead, his wife and daughters are in Europe. He has no money, no job prospects, no place to live and no access to medical services in Algeria."