The event, which will last until Thursday, is expected to attract about 20,000 participants.
Rio de Janeiro Mayor Eduardo Pais said during the opening ceremony that the organization of this event in the Brazilian city constitutes "a crucial stage in an ambitious plan to transform Rio de Janeiro into the capital of innovation in Latin America."
Among the personalities invited to speak during the "Web Summit" in its Brazilian version, former US military analyst Chelsea Manning, who leaked classified documents to WikiLeaks in 2010.
Also speaking at the conference are the presidents of the "Signal" social network, Meredette Whitaker, and Ayo Tomiti, who co-launched the "Black Lives Matter" movement, "Black Lives Matter", against racism and violence against black people.
After its establishment in 2009, the first versions of the "Web Summit" were held in Dublin, and then moved to the capital of Portugal, Lisbon, as of 2016.
The Brazilian version, which will not be a substitute for the one held in the Portuguese capital, Lisbon, will be held in Rio de Janeiro until at least 2028, according to the organizers.
The municipality estimates that the conference will generate approximately R$1.2 billion ($240 million) in the city's economy over the next 6 years.