About 150,000 people gathered in the square to hear to pope's Urbi et Orbi address.
He mentioned several conflicts and epidemics responsible for death across the globe, including those in Ukraine, Syria, Nigeria, Iraq and South Sudan.
"We pray in a particular way for Syria, that all those suffering the effects of the conflict can receive needed humanitarian aid," he said.
"That's it: Happy Easter!" Francis finished, on a lighter note. "Go and have a good lunch!"