- Cass County Conservancy - Preserves the history and culture of the county by promoting and financially supporting projects that represent historical east Texas life. Includes projects, resources, and news.
- Cass County TXGenWeb - Cass County Texas Genealogy and history data.
- Handbook of Texas Online : Cass County - Current and historical information about Cass County.
- The Political Graveyard: Cass County - Lists politicians who lived or died in the county.
