Reversing generations of US attempts to cut Cuba from the outside world, Obama, First Lady Michelle Obama and their two daughters will arrive in Havana for a three-day trip.
It won't just be the first visit by a sitting US president since Fidel Castro's guerrillas overthrew the US- backed government of Fulgencio Batista in 1959, but the first since President Calvin Coolidge came 88 years ago.
For Cubans dreaming of escaping isolation and reinvigorating their threadbare economy, the visit has created huge excitement.
Havana's old town is crawling with painters sprucing up the picturesque streets and the Stars and Stripes - for so long the enemy flag - flutters from numerous buildings.
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The owner of a popular restaurant even put up a poster of Obama, apparently the first ever shown in a country more used to images of revolutionary leaders like Che Guevara.
On the eve of his visit, Obama even cracked jokes with one of the communist country's most loved comedians, Panfilo, in a three and a half minute video sketch released online.
The visit will not resolve all questions - or make everyone happy.
Although Obama has already loosened restrictions on US citizens visiting Cuba, the lifting of the decades-old US economic embargo can only be decided by a Republican-dominated Congress that is far less keen on detente with Raul Castro's Cuba.
Dissidents called on the eve of the visit for Obama to promote "radical change," notably a "stop to repression and use of physical violence against all political and human rights activists."
The Castro government warned Obama ahead of his arrival that lectures on democracy would be "absolutely off the table.