In 1959, he was accepted into the Council of State, having come first in the entrance examination, and served as President of this body between 1966 and 1969.

In the 1974 Greek legislative election, Stasinopoulos became a Member of Parliament in the nationwide ticket of the New Democracy party.

He served as Head of State from 18 December 1974 until 19 July 1975, that is, until the finalization of the new political institutions by the revisionary national assembly through the promulgation of the new Constitution of Greece.

He published many scientific articles and literary works, as well as translations of French poetry and prose.

In 1968 he was elected to the Athens Academy as a full member and in 1969 and 1970 he was put forward by the President of the French Council of State, René Cassin, as a candidate for the Nobel Peace Prize.