Robert Maier was born in Graslitz in 1944. After graduating from high school, he studied mathematics in Giessen and Münster until completing his diploma with a focus on mathematical logic and fundamental research. After leaving the Catholic Church and the Cusanuswerk, he joined the Humanistische Union (Humanistic Union) and the Humanistische Studentenunion (Humanistic Student Union).

In 1969 he joined the FDP (Free Democratic Party), where he became state chairman of the Jungdemokraten North Rhine-Westphalia (Young Democrats, youth organisation of FDP) in 1971. In the FDP he played a decisive role in fundamental decisions of the Jungdemokraten and their paper on the church, whose "lighter" version then became the paper on the church of the FDP. After his studies he worked as a research assistant in a special research area of the German Research Foundation in Heidelberg. In 1974 he married politician Ingrid Matthäus-Maier. After the birth of his second child (1980) he ended his professional career as a mathematician and worked as a househusband and unpaid employee of Ingrid Matthäus-Maier for her political activities. He also held various political positions in the FDP until 1982. In the course of the "turning point" in 1982 he resigned from the FDP and joined the SPD. In 2009 Maier was the sponsor of the Darwin Year (Darwin Patron). Since 2010 he is also a member of the Humanistischer Pressedienst (hpd - Humanistic Press Service).