The aim of this article is to clarify the university teacher roles and competencies in online learning environments, with a view to assisting in the design of professional development activities. This referential framework results from an extensive review of the literature and from analysing professional development designed in different European universities. It is worth mentioning that the definitions that will be produced do not refer to standards of teacher performance; on the contrary, we would like to emphasise the notion of socially situated competencies which are derived from the roles and tasks attributed to university teachers in online learning environments, without losing track of the dialectics and integrity of their exercise. (Contains 1 figure and 1 table.)