Van Rooij works on the semantics  of natural language, informed by insights of cognitive science, and using formal tools from logic, (probabilistic) causal models, and decision and (evolutionary) game theory. 

He studied philosophy and linguistics and obtained his PhD at the 'Institute for Natural Language Processing' (IMS) in Stuttgart (1997). He started working at  the ILLC immediately afterwards, and was appointed professor in 2013. He has been leader of the Logic and Language (LoLa) research unit at the ILLC since 2013, and as such also member of the Management Team. He obtained various national (KNAW, NWO) and international (ERS, ESF) grants for his research and was (and is) a board member of several major (inter-)national projects. Currently, he heads the NWO-sponsored project 'From Learning to Meaning’.

As director of the ILLC, Robert van Rooij will stimulate research that, for example, contributes to a better (logical) understanding of machine learning algorithms, such as those used in particular for the analysis of natural language.