Mayor Mario Landriscina signed the 45-day decree on Friday, which has a stated aim to "protect urban decorum and livability".
Under the new measure, those found violating the ban face fines of €50 to €300 and are also responsible for "restoring the state of the premises at their own expense".
The decree states that homeless people were sometimes "drunk and perform their physiological needs" in central areas of the city, and claimed there had been an "unusual increase" in the number of beggars, both those who beg 'passively' while standing or sitting and those who approach people on the streets.
It goes on to say that the increase in visitors to Como during the Christmas period was one reason for the new order, and also cited "reports from ordinary citizens and commercial businesses" relating to the begging and camping out.
A group of volunteers which has distributed breakfast foods to those sleeping rough for seven years said it was prevented by police from carrying out its work.
"Yesterday morning, we went to the former church of San Francesco in Como to give out breakfast (but above all a chance for social interaction) to people who sleep outside because they have no home. We were forbidden to do so because our simple actions were apparently contrary to the new ordinance," the WelCom group said in a statement.
The volunteers continued: "Continuing to push away the poor does not eliminate poverty, it amplifies it."
At a national level, begging is legal in Italy. And even though it is forbidden to beg with children or animals, enforcement of the law is lax.
But some Italian cities have also adopted their own rules. In 2008, Venice became the first city to take a hardline approach by banning beggars. Fines of between €25 and €50 were introduced for those caught begging, while police can also confiscate their takings. The move was mostly aimed at preventing children from being exploited by criminal groups.