Cass County officials said the man suffered a graze to the head after he fired at the heavily-armoured creature on his property and the bullet ricocheted off and hit him.
The man was taken from his home in the Marietta area to a local hospital to be treated for minor injuries on Thursday, the 'Metro' newspaper reported.
It is not known whether the armadillo has survived.
This is not the first incident where an armadillo bullet deflection has caused injury to a human.