The decision was reached in the early hours of Tuesday morning after late night talks in which the government’s coalition parties clashed over the reopening date, following days of uncertainty for parents, teachers and students.
Secondary students will return to the classroom on January 11, instead of January 7, when younger children will return – but then still only for half of their classes.
The other 50 per cent of classes will remain online.
Several regions have already decided to postpone the reopening of high schools until the end of January, deeming it too risky.
The regional authorities of Veneto and Friuli-Venezia Giulia said they would keep their high schools closed until at least January 31.
Meanwhile, humanitarian organisation Save the Children issued a warning about the potential negative effects of keeping classrooms closed.
Italian teens have only had face-to-face learning for a few months in the past year due to the spring nationwide lockdown and further restrictions imposed at the start of a second wave in autumn.
Save the Children warned on Tuesday that the pandemic had “severely affected” the lives of millions of youngsters and said remote learning had caused “perhaps irreparable damage”.
It published a survey of 14- to 18-year-olds, in which 28 per cent said they had at least one classmate who stopped attending lessons, warning tens of thousands of school students may be dropping out.
The 1000 teens surveyed cited the difficulty in connecting online and lack of concentration, while 37 per cent said their own ability to study had been negatively affected.
Save the Children also warned of the risks to children who do not have the technology or the space at home needed to work online.
On Tuesday, the government also extended the current ban on interregional travel until at least January 15, and confirmed bars and restaurants would stay shut over the weekend of January 9 to 10.
The restrictions were extended as Italy awaits the next set of coronavirus measures to be announced, under the upcoming emergency decree, by January 15.