Lott, 53, gave no final statement before he was given a lethal injection in the state prison in McAlester, the Oklahoman reported. He gave his brother, his only relative present, a brief nod after a curtain was raised to allow witnesses to view the execution,the Oklahoma City newspaper said.
He was pronounced dead 6 minutes after the 6 p.m. execution time.
Lott was the second man to receive a death sentence for the murders of Anna Laura Fowler, 83, in 1986 and Zelma Cutler, 90, in 1987. Robert Lee Miller Jr. was arrested and convicted after he told police his dead grandmother had given him visions of the killings.
Miller was cleared by DNA testing in the 1990s and Lott, who had already served a prison term for burglaries of older women, became a suspect.
Jim Fowler said the case turned him against the death penalty.
"We put the wrong man on death row with my mother," Fowler told the Oklahoman. "The first thing that I can remember when the DNA came out and pinpointed Ronnie Lott ... I said to my wife, 'My God, honey, we could have killed an innocent.'"
Courts rejected a series of last-minute requests for a stay. Lott's lawyers argued he did not get adequate legal representation at his trial.
Lott was the fifth person to be executed in Oklahoma in 2013. A sixth execution is scheduled for Dec. 17.