Jurors convicted Justin Ross Harris, 36, of Georgia, of malice murder and other charges following the death in 2014 of his 22-month-old son, Cooper.
The malice murder conviction means they believed Harris left the boy to die on purpose.
Prosecutors argued through out the trial that Harris was unhappily married and intentionally killed his son because he wanted an escape from family life.
Investigators found evidence Harris was engaging in online flirting as well as affairs with numerous women other than his wife, including a prostitute and an underage teen.
Defence lawyers maintained that Harris was a loving father and that while he was responsible for the boy’s death, it was a tragic accident.