Rui Fernando da Silva Rio is a Portuguese economist and retired politician of the Social Democratic Party (PSD). He was the Mayor of Porto from 2002 to 2013. Between 2018 and 2022, he was President of the PSD and Leader of the Opposition.

The Social Democratic Party is a liberal-conservative political party in Portugal that is currently the country's ruling party. Commonly known by its colloquial initials PSD, on ballot papers its initials appear as its official form PPD/PSD, with the first three letters coming from the party's original name, the Democratic People's Party. A party of the centre-right, the PSD is one of the two major parties in Portuguese politics, its rival being the Socialist Party (PS) on the centre-left.