Mariana Gesteira Ribeiro (born 28 June 1995) is a Brazilian Paralympic swimmer. She competed at the 2020 Summer Paralympics in Tokyo, where she won the bronze medal in the 100 meter freestyle event in the S9 class.
Ribeiro is part of the LGBTQ+ community.
Ribeiro learned to swim at the age of ten. At 14, she was diagnosed with Arnold Chiari syndrome, a condition that affects the brain and nervous system.