The deal, which runs from this season until 2021, gives Facebook exclusive free-to-air rights to 32 live matches each season, including the Champions League final and UEFA Super Cup, the European soccer body said in a statement.
Wednesday highlights and magazine programmes will also be shared each match-week on Facebook's dedicated page, UEFA said.
The first game to be broadcast online will be Wednesday's UEFA Super Cup final between Atletico Madrid and Real Madrid.
UEFA marketing director Guy-Laurent Epstein described it as a "highly innovative and accessible manner" to broadcast games to the region.
Nearly all of Latin America's top players are based with European clubs and many take part in the Champions League every year.
The decision comes a day after Facebook announced a similar deal with Spain's top flight soccer division La Liga.
That deal, which Facebook's Director of Global Live Sports Peter Hutton said was not part of a move into buying up sports rights, will allow viewers in eight nations on the Indian sub-continent to watch every game over the next three seasons for free on the social network.
It also comes as uncertainty surrounds the broadcast of Champions League matches in Brazil, South America's biggest television market.
The current rights holder Esporte Interactivo said last week it would no longer be broadcasting Champions League games on its cable channel but is shifting them to two other non-sports channels owned by the company.
(Reporting by Andrew Downie in Sao Paulo; additional reporting by Brian Homewood, editing by Pritha Sarkar)
