Judge Michael A. Smith said he has "no lingering doubt" that the deadly wildfire that destroyed more than 1,000 homes and charred the northwestern face of the San Bernardino Mountains was caused by Rickie Lee Fowler.
Fowler, 31, was convicted in August of five counts of murder and of arson, the Los Angeles Times reported.
Six men died from heart attacks during the Old Fire in San Bernardino County in October 2003, and the jury blamed Fowler for five of the fatalities.
Fourteen more deaths were subsequently linked to the fire when a Christmas 2003 mudslide on a hillside stripped of vegetation swept through a church camp. Fowler was not charged with causing the slide.
Prosecutors said Fowler started the fire because he was angry his godfather had thrown him out of his house.
Smith cited Fowler's methamphetamine use, violent past, and difficult upbringing by an abusive, drug-addicted mother during the sentencing hearing but said that did not entitle him to mercy. Fowler is already serving three life sentences for attacking a cellmate in court jail.
"I'm glad [Fowler's] going to death row,'' said Jesse Taylor, the son of one of the men who died of a heart attack during the fire. "I think he deserved it because he's been hurting a lot of people for years, not just my father. Not just that fire. For years and years and years he's been hurting people.''