On Wednesday, 189,000 new infections were confirmed in the country of some 59 million people.
"We want to put the brakes on the growth of the curve of contagion and push Italians who are still not vaccinated to do so," Prime Minister Mario Draghi was quoted by an official in his office as telling his ministers.
The cabinet voted unanimously to impose the mandate, which Public Administration Minister Renato Brunetta said puts Italy in the vanguard in Europe in cracking down on those who refuse to be vaccinated and who now account for the majority of patients in Italy's rapidly filling ICU beds.
Some 78 per cent of Italy's population is fully vaccinated. So far, about 36 per cent have received a booster shot.
Draghi said the decision to require vaccination for older people was taken out of concern they are at more risk of hospitalisation and "to reduce the pressure on hospitals and save lives".
It was not immediately announced what if any penalty holdouts might face but Health Minister Roberto Speranza told reporters anyone 50 or older will be checked to see if they have a "super green pass" before they enter their workplace.
That certification is reserved to those who are fully vaccinated or who have recently recovered from COVID-19.
The workplace requirement for older workers takes effect from February 15.
The government also decreed anyone working in universities must be vaccinated, regardless of age.
Currently, vaccination is mandatory for school teachers, healthcare workers, members of the military and police officers.
Also adopted was a requirement that anyone working or obtaining services in beauty parlours and similar establishments must produce a negative virus test if they are not vaccinated or recently recovered from COVID-19.
The same rule will apply to stores in shopping malls and to banks and post offices. Those working in pharmacies or food stores will be exempt.
