Gregory Gillespie (Postmaster)
gregory.j.gillespie@usps.gov
600 Depot St
Mazon, IL 60444
Mazon, IL 60444
The Mazon Post Office is located in the state of Illinois within Grundy County. This location serves 1,761 Mazon residents with a median income of $70,362. It's estimated that approximately 2,811 packages pass through this post office each year.