Ricardo Nuno Pereira Dionísio (born 4 December 1982) is a Portuguese football coach, most recently of Lausanne Ouchy in the Swiss Challenge League.
He then worked under the same capacity with Oscar Londono at Stade Nyonnais during the 2017–18 season, before rejoining Peseiro's staff at Sporting CP in 2018.
Dionísio became a football manager with Stade Nyonnais in 2019, and signed a contract with FC Sion in the Swiss Super League on 1 January 2020, mainly as a caretaker.
In 2021, Dionísio joined Renato Paiva's staff at Independiente del Valle in Ecuador, and followed him to Mexico's León and Brazil's Bahia, the latter one as his assistant.
He returned to the Swiss Super League in late 2023, as he was appointed head coach of FC Stade Lausanne Ouchy, who were promoted in the previous season, on 15 November 2023.