DatesHere is a brief description of each contest; please refer to the Contests & Rules page for more.
- A regular contest refers to a monthly short-answer contest.
- Revenge contests are identical to monthly contests, but accepts problem proposals from students
- The Winter Olympiad is a proof-based contests for teams of up to four.
- The OMO contests are a separate series of contests hosted on internetolympiad.org; they are short-answer contests where teams of four are given over one week to solve thirty problems.
|OMO Fall 2019||Oct 25 - Nov 5, 2019||Fri - Tue|
|OMO Spring 2020||Mar 27 - Apr 7, 2020||Fri - Tue|
|OMO Fall 2018||October 26 - November 6, 2018||Fri - Tue|
|OMO Spring 2019||March 22 - April 2, 2019||Fri - Tue|
|Fall OMO 2017||October 27 - November 7, 2017||Fri - Tue|
|Spring OMO 2018||March 23 - April 3, 2018||Fri - Tue|
|Contest 27||September 26, 2016||Mon|
|Contest 28||October 18, 2016||Tue|
|Fall OMO 2016||November 4 - 15, 2016||Fri - Tue|
|Contest 29||November 30, 2016||Wed|
|Contest 30||February 16, 2017||Thu|
|Spring OMO 2017||March 24 - April 4, 2017||Fri - Tue|
|April Fun Round||April 1, 2017||Sat|
|Revenge 31||April 7, 2017||Fri|
|Contest 32||May 11, 2017||Thu|
|Contest 20||September 23, 2015||Wed|
|Contest 21||October 16, 2015||Fri|
|Fall OMO 2015||November 6 - 17, 2015||Fri - Tue|
|Revenge 22||December 8, 2015||Tue|
|Contest 23||January 7, 2016||Thu|
|Contest 24||February 22, 2016||Mon|
|Spring OMO 2016||March 18 - 29, 2016||Fri - Tue|
|April Fun Round||April 1, 2016||Fri|
|Revenge 25||April 5, 2016||Tue|
|Contest 26||May 12, 2016||Thu|