The service is Wednesday morning at a union hall in the Chicago suburb of Countryside. Among those expected to speak are Gov. Pat Quinn, Gov.-elect Bruce Rauner and former Gov. Jim Thompson.
Topinka died last week at age 70 after suffering complications from a stroke. The Republican also served as state treasurer and was a former head of the state GOP.
A spokesman says Topinka didn't want a funeral or wake, but had said friends and family could hold a memorial service.
Others expected to speak at the service include Illinois Auditor General William Holland and Topinka's former chief of staff, Nancy Kimme.
