Ryan made the announcement as he spoke before the University of Illinois College of Law on the state's death penalty system. Ryan has been considering commuting the death sentences of about 140 men currently on death row. The men he pardoned Thursday already had been released.
"I wish them well; they've been through hell," Ryan said as the crowd gave him a lengthy ovation.
The pardons, which had been widely expected, came a day after federal prosecutors released papers alleging that Ryan had personal knowledge of wrongdoing by aides in the secretary of state's office he ran before being elected governor in 1998.
The governor issued a statement Wednesday saying he had a "clear conscience." He made no statement to reporters Thursday morning.
Ryan has the power to grant clemency to all 160 inmates facing execution in Illinois, but he has said recently that a blanket clemency is unlikely.
The Republican governor, who did not seek re-election, leaves office Jan. 13.
His latest actions follow months of emotional pleas from lawyers and others who are convinced that Illinois' death penalty system is hopelessly flawed, and counter-pleas from the families of victims of some of the most terrible crimes in the state's history.
Ryan gained national prominence when he halted executions nearly three years ago, calling the state's death penalty system "fraught with error" after the courts found that 13 men on death row had been wrongly convicted since the state resumed capital punishment in 1977.
He pushed for a sweeping overhaul of the way capital cases are handled. Ryan later raised the possibility that he would commute the sentences of everyone facing execution. That led most of the death row inmates to file formal petitions for clemency.
Cruz served 11 years in prison, including seven on death row, for the 1983 rape and murder of 10-year-old Jeanine Nicarico. At a third trial, he was acquitted after a police officer changed his story about an incriminating statement Cruz supposedly made. DNA evidence later pointed to someone else as the rapist.
Also pardoned was Gary Gauger, who said he wants to clear his name and seek compensation after being wrongly convicted of killing his parents. Prosecutors opposed his pardon, though they did not dispute that 74-year-old Morris Gauger and 70-year-old Ruth Gauger were killed by members of the Outlaws motorcycle gang.
The third pardon went to Steven Linscott, who was convicted of murdering a young woman in suburban Chicago. Then a college Bible student managing a Christian halfway house with his wife, he told police about a strange dream he had, which in some ways was similar to the attack.
The police considered it a confession. He ended up going to prison for more than three years before his conviction was overturned by an appellate court and subsequent DNA testing exonerated him.