Illinois State Route 163 is a north-south highway in St. Clair County. This runs from Illinois State Route 15 at Alorton to Illinois State Route 158 at Millstadt. IL St Rt 163 passes through the following towns in St. Clair County. Cahokia Heights (former Village of Alorton, Village of Cahokia, Village of Centreville; prior to May, 2021)
The western end at IL St Rt 15. The western end marker. A St. Clair County mile marker. A junction marker on WB IL St Rt 13/SB IL St Rt 157. NB IL St Rt 157/163 south of IL St Rt 13. SB IL St Rt 157/163 in Centreville. NB IL St Rt 157/163 north of SB IL St Rt 163. SB IL St Rt 163 near Westview. A junction marker on WB IL St Rt 158. The eastern end of IL St Rt 163. The eastern end marker.
