U.S. Census Bureau: Williamson County, Illinois
- Area map plus population, demographic, and housing information from the latest census.
- http://quickfacts.census.gov/qfd/states/17/17199.html

American History and Genealogy Project, The: Williamson County, Illinois
- A genealogy and history site which includes many records and where county and surname researchers can submit material, connect, and help each other.
- http://www.rootsweb.com/~ilwillia

Shawnee Library System
- Includes information on services, contacts, and the Board of Directors.
- http://www.shawls.lib.il.us/

Illinois Clean Coal Institute (ICCI)
- Research and development program with emphasis on continued utilization, environmentally clean burning, and new markets for Illinois Basin coals. News and events, research, and staff listing.
- http://www.icci.org/

The John A. Logan College Community Band
- Information about the band and its members, officers, and director.
- http://www.jal.cc.il.us/band.html

Tiger Map Server Browser
- Map based on census material for Williamson county.
- http://tiger.census.gov/cgi-bin/mapbrowse?lat=37.7303&lon=-88.9295&wid=.3&ht=.3&mlat=37.7303&mlon=-88.9295&msym=redpin&mlabel=Williamson+County,+IL

NPIN/Illinois: Organizations: Williamson County
- Services and Resources: Williamson County
- http://npinil.crc.uiuc.edu/resource/williams.html

Resources for Williamson county
- Listing of services in Williamson county
- http://www.egyptianaaa.org/WilliamsonCounty.htm

The Political Graveyard: Williamson County, Ill.
- Politicians who were born or lived in Williamson county
- http://politicalgraveyard.com/geo/IL/WL.html