Overview
The Olimpíada Brasileira de Matemática (OBM) is Brazil's national mathematics olympiad for secondary and early university students, run by the Sociedade Brasileira de Matemática (SBM). Its main purpose is to select and train the students who represent Brazil at international competitions such as the International Mathematical Olympiad (IMO) and the Ibero-American Mathematical Olympiad.
Who can apply
OBM has levels for Nível 1, Nível 2, Nível 3 (secondary school students) and a university level, open to students enrolled through their school or university.
Exam pattern
For the 48th edition, OBM was held over two days, 8–9 October 2026, starting at 2:00 pm Brasília time each day. Students register for their level through the selection window set each year; for 2026, selection ran from 7 September to 2 October, with the same 2 October deadline to confirm participation.
After the exam
OBM results feed into Brazil's selection and training process for international teams, including the IMO and the Ibero-American Mathematical Olympiad — Brazil has competed at the Ibero-American Olympiad and hosted the IMO itself in Rio de Janeiro in 2017.
Preparation tips
Use past OBM papers and the SBM's Revista Eureka!, a magazine the society publishes specifically to help students prepare for OBM and international olympiads.
Work through material by level, since Nível 1 through Nível 3 and the university level use different problem sets.
FAQs
Who runs the OBM?
The Sociedade Brasileira de Matemática (SBM).
What is the OBM used for?
It selects and trains the students who go on to represent Brazil at the International Mathematical Olympiad and the Ibero-American Mathematical Olympiad.