Isenburg-Büdingen-Birstein was a County of southern Hesse, Germany, located to the north of Gelnhausen. Isenburg-Büdingen-Birstein was created as a partition of Isenburg-Büdingen in 1511, and was partitioned into Isenburg-Birstein, Isenburg-Büdingen, and Isenburg-Offenbach in 1628.