Winnebago County Jail
Winnebago County Jail
County JailMailing Address
[Inmate Full Name] — [Booking/ID]
Winnebago County Jail
P.O. Box 247
Phoenix, MD 21131
Winnebago County Jail
P.O. Box 247
Phoenix, MD 21131
Physical Address
4311 Jackson Street, Oshkosh, WI 54901
Governing Agency
Winnebago County Sheriff's Office
Inmate ID
Inmate / Booking ID — Required
Last Verified
September 29, 2026
Facility Mailing and Service Information
Personal correspondence is processed off-site; legal/privileged mail and certain exempt items follow separate direct-facility procedures.
Last verified: September 29, 2026
Photographs must comply with current Winnebago County scanning/content restrictions.
Last verified: September 29, 2026
Books and publications follow separate Winnebago County rules.
Last verified: September 29, 2026
Use approved Winnebago County inmate-account deposit methods; do not send cash with personal mail.
Last verified: September 29, 2026
Verify current visitor approval, identification and scheduling requirements before travel.
Last verified: September 29, 2026
How to Address Your Letter
Ordinary personal mail is processed off-site through the Phoenix, Maryland address. Include the inmate's full name and booking/ID number and verify current Winnebago County correspondence rules.
About Winnebago County Jail
Winnebago County Jail is physically located in Oshkosh, Wisconsin. Personal mail is routed through an off-site Phoenix, Maryland processing center.