Spyridon "Spyros" Markezinis was a Greek politician, longtime member of the Hellenic Parliament, and briefly the Prime Minister of Greece during the aborted attempt at metapolitefsi (democratization) of the Greek military regime in 1973.

A minister without portfolio is a government minister without specific responsibility as head of a government department. The sinecure is particularly common in countries ruled by coalition governments and a cabinet with decision-making authority wherein ministers without portfolio, while they may not head any particular offices or ministries, may still receive a ministerial salary and have the right to cast a vote in cabinet decisions. The office may also exist to give party leaders whose offices would not otherwise enable them to sit in Cabinet.