- Park Forest
- Park Ridge
- Parkersburg
- Patoka
- Patterson
- Paw Paw
- Pawnee
- Paxton
- Payson
- Pearl
- Pearl City
- Pecatonica
- Pekin
- Pembroke Township
- Penfield
- Peoria
- Peoria Heights
- Peotone
- Percy
- Perks
- Perry
- Peru
- Pesotum
- Petersburg
- Philo
- Piasa
- Pierron
- Pinckneyville
- Piper City
- Pittsburg
- Pittsfield
- Plainfield
- Plainville
- Plano
- Plato Center
- Pleasant Hill
- Pleasant Plains
- Plymouth
- Pocahontas
- Polo
- Pomona
- Pontiac
- Poplar Grove
- Port Byron
- Posen
- Potomac
- Prairie City
- Preemption
- Princeton
- Princeville
- Prophetstown
- Prospect Heights
- Pulaski
- Putnam
- Quincy
- Radom
- Raleigh
- Ramsey
- Rankin
- Ransom
- Rantoul
- Rapids City
- Raritan
- Raymond
- Red Bud
- Reddick
- Redmon
- Renault
- Reynolds
- Richmond
- Richton Park
- Richview
- Ridge Farm
- Ridgway
- Ridott
- Rinard
- Ringwood
- Rio
- River Forest
- River Grove
- Riverdale
- Riverside
- Riverton
- Roanoke
- Robbins
- Roberts
- Robinson
- Rochelle
- Rochester
- Rock City
- Rock Falls
- Rock Island
- Rockbridge
- Rockford
- Rockport
- Rockton
- Rockwood
- Rolling Meadows
- Rome
- Romeoville
- Roodhouse
- Rosamond
- Roscoe
- Roselle
- Roseville
- Rosiclare
- Rossville
- Round Lake
- Roxana
- Royal
- Royalton
- Rushville
- Russell
- Rutland
- Sadorus
- Sailor Springs
- Saint Anne
- Saint Augustine
- Saint Charles
- Saint David
- Saint Elmo
- Saint Francisville
- Saint Jacob
- Saint Joseph
- Saint Libory
- Saint Peter
- Sainte Marie
- Salem
- San Jose
- Sandoval
- Sandwich
- Saunemin
- Savanna
- Savoy
- Sawyerville
- Saybrook
- Scales Mound
- Schaumburg
- Scheller
- Schiller Park
- Sciota
- Scott Air Force Base
- Scottville
- Seaton
- Seatonville
- Secor
- Seneca
- Serena
- Sesser
- Seward