A federal jury found Richard Boyle, from Doylestown, guilty of 11 separate bank robberies.
The crimes happened in Montgomery and Bucks Counties between 2012 and 2016.
In all, he got away with nearly $500,000.
Boyle will be sentenced in July.
Authorities say when he started robbing banks in 2012 he had just gotten out of prison for a different bank robbery spree.