Diogo Eurico Vaz de Bacelar da Fonseca e Costa (born 23 August 1997) is a Portuguese sailor.

He competed in the 2020 Summer Olympics.

[1] Costa placed second in the 2021 470 World Championships with Pedro Costa, qualifying the pair for the 2020 Olympics.

[2] He and Carolina João won a place to compete in the 2024 Olympics as did the ILCA 7 sailor Eduardo Marques and the kitefoiler Mafalda Pires de Lima.

This biographical article related to sailing in Portugal is a stub.