Dennis Auerswald, 60, of Medina was convicted in March of aggravated murder after a two-week trial, The (Cleveland) Plain Dealer reported. His wife Maureen, 60, died in February 2009.
At his sentencing before Medina County Common Pleas Judge Christopher Collier, Auerswald said, "As God is my witness, I had nothing to do with my wife's death."
He has no chance for parole for 30 years.
Prosecutors said Auerswald's motive was to get his wife's $100,000 life insurance policy and Social Security benefits and to see other women.
Prosecutor Dean Holman put forth the case that Auerswald poisoned his wife's cranberry juice in a plastic cup that was never found.
The defense said there was no direct evidence implicating Auerswald and suggested Maureen Auerswald may have committed suicide.