A Florida man was arrested with enough of the narcotic fentanyl to kill half a million people, cops revealed Tuesday.

David Gayle, 43, was arrested for dealing drugs — including two charges stemming from warrants for selling heroin within 1,000 feet of a church — when detectives with the Hernando County Sheriff’s Office executed a search warrant April 24 for his Brooksville home.

Investigators discovered more than two pounds of the synthetic drug fentanyl and methamphetamine, a mixture sometimes called a “goofball.”

This amount of fentanyl can “potentially” kill 500,000 people, according to a press release from the sheriff’s office.

“We can never measure what we prevent, but it is a very good bet that this quantity of fentanyl would have resulted in a number of overdose deaths right here in Hernando County,” said Sheriff Al Nienhuis in the release.

Cops also found more than almost seven grams of cocaine, a gram of oxycodone and 13 grams of hashish — as well as some marijuana and drug paraphernalia.

Gayle was charged one count of trafficking fentanyl and one count of trafficking methamphetamine — as well as separate counts of possession for each of the other drugs found.

Jail records show Gayle has an extensive criminal background in Hernando County, mostly for cocaine possession, since 2011.

He was being held Tuesday in the Hernando County jail in lieu of a $215,000 bond and faces life in prison if convicted.