Open Access (OA) initiatives and knowledge infrastructure represent vital elements for both producing significant changes in scholarly communication and reducing limitations of access to the circulation of scientific knowledge in developing countries. The spreading of the OA movement in Latin America and Caribbean (LA&C) countries, exemplified by the growth of regional and national initiatives, such as the creation of OA digital journal libraries and the establishment of supportive governmental policies, provides evidence of the significant role OA is playing in improving the participation of LA&C countries in the so-called "global knowledge commons". In this paper, we map OA publications in LA&C countries through a bibliometric analysis of OA publications indexed by the Web of Science Core Collection and SciELO Citation Index during the period 2005-2017. Searches were done in the fields "Country", "Publication Year", "Language", and "Research Area" using WoS analytical tools, in order to map the evolution, distribution, and characteristics of OA publications in the LA&C region. The analysis is conducted on both the sub-regional and national levels. On the sub-regional level, trends in the four LA&C sub-regions (Southern Cone, Central America and Mexico, Andes, and the Caribbean) are identified and compared. On the national level, the analysis identifies as most representative and focuses on nine countries: Argentina,