His passing comes just one year after another contestant, Dr Brandon Rogers, 29, was killed in a vehicle accident weeks before his AGT audition was due to air on TV.
The pop opera singer's cause of death was heart failure, but there will not be an autopsy to confirm. TMZ reported that he had a known health condition released to his heart.
Just a year before his passing, Boyd and his mother, Esther, were in a major auto accident after he blacked out behind the wheel. It has not yet been revealed whether or not his heart failure is related to his accident.
He was involved in a near-fatal wreck past year after blacking out behind the wheel and running into two trees. The two were rushed to hospital at the time, with TMZ claiming that both Neal and his mother had been "slowly recovering" since then.
Following his America's Got Talent victory in the NBC show's third season, Boyd recorded one album, My American Dream. He released one single from the project, "God Bless the US", though it failed to chart.
The former insurance salesman ran for Missouri House of Representatives in 2012 as a Republican, ultimately losing out to Democratic incumbent Steve Hodges. Neal ran on a conservative platform and wanted to "fight to Repeal Obamacare", per an archived look at his campaign site.