Cubans are fervently hoping the Pope's visit will help further improve relations with the United States, which lies just 145km across the Florida Straits, and help to lend moral legitimacy to Havana's demand that Washington lift its trade embargo.
It was just before Christmas that it emerged that the Pope had secretly hosted talks in the Vatican between American and Cuban officials. This mediation culminated in the old enemies restoring normal diplomatic ties.
While the Pope is not expected openly to criticise the authoritarian rule of Raul Castro and his elder brother Fidel, he could deliver the message implicitly by choosing to meet a dissident group - possibly the Ladies in White, a group of women who stage anti-Castro protests after attending church.
He may use the discreet, coded language at which the Vatican excels, stopping short of lambasting the Castros, but stressing the importance of democracy and diversity.
"Often, these types of problems are dealt with in conversations, not so much with public proclamations but in personal, direct or private discussions," said Vatican spokesman Father Federico Lombardi.
The first Latin American Pope is likely to push for greater freedoms for the Catholic Church. Almost extinguished during the early decades of the revolution, it has since the 1990s been given greater leeway.
Today, the church plays a vital role in running charities for struggling Cubans. It has ventured into public education, opening cultural centres which provide courses in everything from humanities and languages to business administration.
"All of these activities are eating away at the revolution's myth that the state can take care of people from the cradle to the grave," said Austen Ivereigh, a Vatican analyst. But the church wants far greater concessions, including permission to re-establish Catholic schools and access to state radio and television networks.
