Fernando Codá dos Santos Cavalcanti Marques (born 8 October 1979) is a Brazilian mathematician working mainly in geometry, topology, partial differential equations and Morse theory.

[1][2] Codá Marques started as a student of civil engineering at the Federal University of Alagoas in 1996, but switched to mathematics after two years.

[5] Following the advice of Manfredo do Carmo, Codá Marques went to Cornell University to learn geometric analysis from José F. Escobar, so that he could return and bring this area of research to Brazil.

[7] He obtained his Ph.D. from Cornell University in 2003, under the supervision of José F. Escobar (thesis: Existence and Compactness Theorems on Conformal Deformation of Metrics).

Codá Marques faced the difficulties of doing research in isolation, so he decided to accept an invitation to stay one year as a postdoc at Stanford University.

There he was influenced by Richard Schoen's school of thought in geometry and met André Neves (who would become his main collaborator), and many other of his contacts.

In April 2010, in cooperation with Simon Brendle and André Neves,[15] Marques provided a counter-example to the rigidity conjecture of Min-Oo.

[30] The citation reads: "His recent work, in collaboration with André Neves, developed a full Morse theory for the area functional in closed Riemannian manifolds.

"[31] In 2021, he was awarded the Fermat Prize, "for major advances obtained with André Neves on geometric applications of the calculus of variations".