A Metra spokesperson said the collision happened at the Schaumburg station. An outbound train hit the woman, whose condition was not immediately known.
A Metra alert initially said inbound and outbound Milwaukee District West trains were halted near the station, but a spokesperson later told ABC7 that one of two tracks had been reopened.
Extensive delays were expected.
Authorities did not immediately provide further information.
This is a developing story. Check back with ABC7 for updates.