Roberto Castelli (born 12 July 1946) is an Italian politician.

[2] Initially, the then Italian president Carlo Azeglio Ciampi, even though he had been pressured by Castelli to do so, refused to sign the bill.

[3] As a minister, Castelli refused to sign Ciampi's decision to pardon Adriano Sofri, leading to a conflict of powers in which Ciampi, as the president of the Italian Republic, tried to reassert its exclusive competence in the matter (as stated in article 87 of the Constitution of Italy), and Castelli claimed that, as justice minister, he had the right to object.

He also refused to request the extradition of 22 alleged CIA agents from the United States who were implicated in the kidnapping and torture of Hassan Mustafa Osama Nasr.

On 13 December 2012, Castelli said during the satirical talk show of Rai Radio 2 Un giorno da pecora that he would not seek re-election to the 2013 Italian general election.