Both parents left their religion to join the Italian Theosophical Society, for which Roberto Hack was secretary for a time under the chairmanship of the countess Gamberini-Cavallini.

[5] Hack attended the Liceo Classico "Galileo Galilei" in Florence, but the outbreak of World War II prevented her from taking her exams.

In 1945, she received a degree in physics from the University of Florence with a final score of 101/110;[6] her thesis in astrophysics was on Cepheid variables, based on her studies in the Arcetri Observatory, then under the direction of Giorgio Abetti.

[15][16] In June 2022, to celebrate the 100th anniversary of her birth, a statue of Margherita Hack was placed in front of the Università Statale di Milano.

[25] In Italy, with an intensive promotion work, she obtained the growth of activity of the astronomical community with access to several satellites, reaching a notoriety of international level.

[27] Hack also believed that ethics does not derive from religion, but from "principles of conscience" that allow anyone to have a secular view of life, respectful of other people's individuality and freedom.

[27] Hostile to any form of superstition, including pseudosciences, Hack was a scientific guarantor of CICAP since 1989 and an honorary president of the Union of Rationalist Atheists and Agnostics (UAAR).

On 22 October 2008, during a student demonstration in Piazza della Signoria in Florence, Hack gave a lecture on astrophysics touching on the experiments carried out at the CERN about the Higgs boson, after a discussion against the law 133/08 (which previously was the law-decree 112, called "Tremonti decree").

In November 2009, through an open letter on the MicroMega magazine, she criticized the Italian President of the Council, Silvio Berlusconi, on the matter of legal actions in which he was involved in and his alleged attempt to elude them.

[32] In October 2012 she declared her endorsement for Nichi Vendola during the left wing primary elections, whereas during the following ballot she sided for Matteo Renzi against Pierluigi Bersani.