The 24 Community
- Cast, character, episode, and spoiler discussion board. [Registration required.]
- http://z14.invisionfree.com/The_24_Community/

24Natic
- Episode, cast, character, spoiler, and fan fiction discussion. [Registration required.]
- http://s7.invisionfree.com/24natic

24 Forum
- Cast, episode, and spoiler discussion.
- http://forums.prospero.com/fox24/start

Yahoo! Groups: 24UK
- Message board. Spoilers for U.K. viewers discouraged. [Yahoo! registration required.]
- http://tv.groups.yahoo.com/group/24UK/

Yahoo! Groups: fox_24
- Discussion board for viewers. [Yahoo! registration required.]
- http://tv.groups.yahoo.com/group/fox_24/

Yahoo! Groups: 24_Over_30
- Discussion board with membership limited to people older than 30. Includes spoilers. [Yahoo! registration required.]
- http://tv.groups.yahoo.com/group/24_Over_30/

Yahoo! Groups: 24_fans
- Topics focus on the show as well as Kiefer Sutherland. [Yahoo! registration required.]
- http://tv.groups.yahoo.com/group/24_fans/

Yahoo! Groups: Twenty_Four
- Discussion of the series. [Yahoo! registration required.]
- http://groups.yahoo.com/group/Twenty_Four/

Yahoo! Groups: 24-FanFiction
- Members post stories based on the series. [Yahoo! registration required.]
- http://groups.yahoo.com/group/24-FanFiction/