The tourist from North Rhine-Westphalia was on a bike ride with her husband in Mecklenberg-Western Pomerania when the incident happened.
The pair were crossing a field near the town of Gadebusch when they unknowingly entered the path of a boar hunt and the woman suddenly felt a pain in her chest.
She than saw that she had been hit by a rebounded shot - but the underwire of her bra had deflected the blow, 'Gadebusch-Rehnaer Zeitung' reported.
"Those in charge of the hunt then broke it up straight away," said police spokesperson Andre Falke.