Artur Oscar Lopes (born on 17 October 1950 in the city of Rio de Janeiro) is a Brazilian mathematician working on dynamical systems and ergodic theory. He is a professor at UFRGS, Porto Alegre.
He earned his Ph.D. from the IMPA in 1977 under the supervision of Jacob Palis.
He is a recipient of Brazil's National Order of Scientific Merit in mathematics. Since 2007 he has been a member of the Brazilian Academy of Sciences.
He is the author of the textbooks Tópicos de Mecânica Clássica, Cálculo Tensorial, Teoria dos Corpos, and Equações Diferenciais Ordinárias.