The Miami Herald reported Pardo, 56, died by lethal injection at 7:47 p.m. Tuesday at the Florida State Prison near Starke.
The newspaper said before Pardo was put to death he spent time with eight relatives and friends and ate a Cuban-style last meal.
Corrections spokeswoman Ann Howard said he also met with a prison chaplain and retired Catholic Bishop John Snyder.
"After visiting with family and friends, it's best to describe him as calm," Howard said.
His execution came after a last-minute appeal to stay it was rejected Tuesday afternoon by the U.S. Court of Appeals. A federal judge in Jacksonville also had declined Monday to interfere with the state's implementation of his punishment.
Pardo and an accomplice primarily targeted drug dealers, authorities said. At his trial, Pardo described himself as "a soldier" who was ridding the streets of the "scum of the Earth."
"As a soldier, I ask to be given the death penalty," he said then.