THOTCON is an American hacker conference that is organized by Nicholas J. Percoco, Matt Jakubowski, Jonathan Tomek, John Mocuta, David "VideoMan" Bryan and several other OPERs (volunteers from the local DEF CON 312 chapter) . It is held in Chicago, Illinois United States at a somewhat different Top Secret location each year.
The conference was historically held on a single day but since 2015 with growing popularity now covers two days. Originally the con featured a single track of speakers presenting between 10-12 talks on various information security and hacking topics. Currently, the conference offers multiple tracks including full-length talks, shorter 'TURBO' talks, longer workshops and villages.
The name THOTCON is made of the first letter in the words that represent the main Chicago Area Code (312); as in THree-One-Two.
- The conference had approximately 235 attendees and 8 talks. It was also the very first hacker conference to be held in Chicago.
- THOTCON 0x2 was held on April 15, 2011 at Joe's Bar in Chicago, IL.
- The conference had approximately 336 attendees and 12 talks.
- THOTCON 0x3 was held on April 27, 2012 at 4025 N Ravenswood, Chicago, IL.
- The conference had approximately 500 attendees and between 10 and 20 talks depending on the final venue configuration.
- THOTCON 0x4 was held on April 26, 2013 at 4025 N Ravenswood, Chicago, IL.
- The conference had approximately 700 attendees and featured 9 full-length talks, 9 shorter 'TURBO' talks and 3 workshops.
- THOTCON 0x5 was held on April 25, 2014 at 4025 N Ravenswood, Chicago, IL.
- THOTCON 0x6 was held on May 14th &15th, 2015 at 4025 N Ravenswood, Chicago, IL.
- THOTCON 0x7 was held on May 5th &6th, 2016 at 4025 N Ravenswood, Chicago, IL.
- THOTCON 0x9 was held on May 5th &6th, 2018 at 44626 N Knox Ave, Chicago, IL.
THOTCON is produced by THOTCON Infinity NFP, a tax-exempt 501(c)(3) nonprofit organization. 
Past speakers of THOTCON events have included:
- Bruce Schneier, an American cryptographer, computer security and privacy specialist, and writer.
- Jayson E. Street, author of "Dissecting the hack: The F0rb1dd3n Network"
- Rafal Los, author of the HP blog: "Following the White Rabbit"
- Ryan Jones, star of the TV show Tiger Team (TV series)
- Dave Marcus, director of security research at McAfee
- G. Mark Hardy, president of National Security Corporation
- Samy Kamkar, a prolific American programmer, freelance security researcher, and hacker
- Cory Doctorow, a Canadian science fiction author, activist, journalist, blogger and Special Advisor to the Electronic Frontier Foundation
- "DEFCON 312 Local Group". DC312. Archived from the original on 2011-02-27. Retrieved 2010-12-31.
- "[Interview] c7five - "THOTCON co-creator and "". Digital Soapbox - Down the Security Rabbithole!. 2010-04-02. Archived from the original on 2011-07-08. Retrieved 2010-12-31.
- "THOTCON - Chicago's Hacking Conference".
- Dissecting the hack: The F0rb1dd3n Network
- Following the White Rabbit
- Dave Marcus, McAfee Labs Team>
- G. Mark Hardy
- "Cory Doctorow". Electronic Frontier Foundation. 2011-10-07. Retrieved 2018-07-16.