- Radom
- Rankin
- Ransom
- Rantoul
- Rapids City
- Raritan
- Raymond
- Red Bud
- Reddick
- Redmon
- Rentchler
- Reynolds
- Richmond
- Richton Park
- Richview
- Ridge Farm
- Ridgway
- Ridott
- Ringwood
- Rio
- Ripley
- River Forest
- River Grove
- Riverdale
- Riverwoods
- Roanoke
- Robbins
- Roberts
- Robinson
- Rochelle
- Rock City
- Rock Falls
- Rock Island Arsenal
- Rockbridge
- Rockdale
- Rockton
- Rockwood
- Rogers Park
- Rolling Meadows
- Rome
- Romeoville
- Roodhouse
- Roscoe
- Rose Hill
- Roselle
- Rosewood Heights
- Rosiclare
- Rossville
- Round Lake
- Round Lake Beach
- Round Lake Heights
- Round Lake Park
- Roxana
- Royal
- Royal Lakes
- Royalton
- Ruma
- Rushville
- Russellville