Places beginning with PI in Illinois, United States
- Piankashawtown (historical)
- Piasa
- Piasa Hills
- Piasa, Township of
- Piatt
- Piatt County
- Pickaway, Township of
- Pierceburg
- Pierces Park (subdivision)
- Pierce, Township of
- Pierron
- Pierron
- Pierson
- Pigeon Grove, Township of
- Pigeon (historical)
- Pike
- Pike County
- Pike, Township of
- Pilot Center (historical)
- Pilot Grove, Township of
- Pilot Knob, Township of
- Pilot, Township of
- Pilot, Township of
- Pilsen (subdivision)
- Pinckneyville
- Pinckneyville Number 1 Election Precinct
- Pinckneyville Number 2 Election Precinct
- Pinckneyville Number 3 Election Precinct
- Pinckneyville Number 4 Election Precinct
- Pinckneyville Number 5 Election Precinct
- Pinckneyville Number 6 Election Precinct
- Pinckneyville Number 7 Election Precinct
- Pinckneyville Number 8 Election Precinct
- Pine Creek, Township of
- Pine Grove
- Pine Grove (subdivision)
- Pinehurst Manor
- Pine Lake Circle (subdivision)
- Pine Manor (subdivision)
- Pine Meadow Estates
- Pine Rock, Township of
- Pine Valley (subdivision)
- Pine View
- Pingree Grove
- Pinhook (historical)
- Pinkstaff
- Pin Oak, Township of
- Pioneer
- Piopolis
- Piper City
- Pisgah
- Pisgah Election Precinct
- Pistakee
- Pistakee Highlands
- Pitcherville (historical)
- Pitchin
- Pitman, Township of
- Pittsburg
- Pittsburg
- Pittsfield
- Pittsfield, Township of
- Pittwood
- Pixley, Township of