(FILES) Tunisia's President Kais Saied .AFP
Hachani took office on August 1 last year, replacing Najla Bouden, who was also dismissed without an official reason by Saied.
His replacement Madouri had only taken on the social affairs portfolio in May.
In a social media post from his office, Saied is shown shaking hands with Madouri with a brief statement saying only that the president had "decided to assign him to head the government, succeeding Mr. Ahmed Hachani".
Saied, 66, is now seeking another term in office in elections on October 6.
He submitted his official candidacy for the election on Monday, while some would-be challengers are being barred from running, including through prosecution and imprisonment.
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