Canada National competitions hosted by Mathematica : The Mathematics Contest Centre:Multiple Choice:

• Newton Contest (9th grade students)
• Lagrange Contest (8th grade students)
• Euler Contest (7th grade students)
• Pythagoras Contest (6th grade students)
• Fibonacci Contest (5th grade students)
• Byron-Germain Contest (4th grade students)
• Thales Contest (3rd grade students)

National competitions hosted by The Centre for Education in Mathematics and Computing:Full Solutions: Euclid (12th grade students)

• Hypatia (11th grade students)
• Fryer (9th grade students)

Multiple Choice: Fermat (11th grade students) Cayley (10th grade students)

• Pascal (9th grade students)
• Gauss (7th and 8th grade students)

Other competitions hosted by The Canadian Mathematical Society:

• Canadian Open Mathematics Challenge
• Canadian Mathematics Olympiad, the official mathematical Olympiad of Canada and its International Mathematical Olympiad TST, or team selection test.

MATHChallengers (formerly MathCounts BC) is called MathChallengers since 2005. It is hosted by APEGBC

China CMO (China Mathematics Olympiad) CWMO (Western China Mathematics Olympiad)

• CSMO (South-eastern China Mathematics Olympiad) — for secondary 4 students

Czech Republic MO (Czech National Mathematics Olympiad, http://www.math.muni.cz/~rvmo)

• Vojtech Jarnik Competition (International Mathematics Competition for University Students held annually in Ostrava, http://jarnik.osu.cz/)
• PraSe (Prague Mathematics Correspondence Seminar for Secondary School Students, http://mks.mff.cuni.cz)
• Brkos (Brno Mathematical Correspondence Seminar for Secondary School Students, http://www.math.muni.cz/~brkos)

DenmarkGeorg Mohr (Contest for Danish high school students, see http://www.georgmohr.dk/