The seat was named after the town of Wagin and incorporated portions of the Wheatbelt, albeit with varying boundaries.
Wiese was succeeded by current member and National MP Terry Waldron at the 2001 state election.
Waldron held the seat until Wagin was abolished in a redistribution prior to the 2017 state election.
In its last incarnation, Wagin was a large rural electorate in the southern part of the Wheatbelt region.
Its major population centres included Cuballing, Boddington, Brookton, Corrigin, Gnowangerup, Hyden, Lake Grace, Katanning, Kojonup, Narrogin and Wagin.