Géza Alföldy was born in Budapest. He studied at the Faculty of Humanities of the University of Budapest from 1953 to 1958, where he in 1959 received a doctorate.[4] Alföldy worked at the Budapest city museum from 1957 to 1960, and from 1960 to 1965 he was an assistant professor at the Institute for Ancient History at the University of Budapest. In 1965, he emigrated to West Germany, where he initially worked at the Bonn Rhenanian State Museum from 1965 to 1968. During this time, Alföldy earned a habilitation at the University of Bonn in 1966, where he served as a university lecturer and eventually as a full professor. In the same year he became professor of Ancient History at the Ruhr University Bochum. Alföldy was appointed professor for Ancient History at the University of Heidelberg in 1975 and stayed there until his retirement in 2002. After the renewal of his professorship, Alföldy taught as a substitute professor until 2005. He died in 2011 whilst visiting Athens, Greece.
In the 1990s, Alföldy also concerned himself with the modern history of his native Hungary.
Within the scope of his epigraphical studies, Gezá Alföldy visited many countries (Albania, Algeria, Austria, Britain, Cyprus, Egypt, France, Greece, Hungary, Italy, Jordan, Libya, Portugal, Spain, Syria, Turkey, Tunisia, and Yugoslavia) in order to research original ancient inscriptions.
In addition, he continued to deliver diverse academic lectures both in and outside Germany, while supervising scores of new academics during their promotion or habilitation phases (more than one dozen alone since 1992).
Alföldy was also co-editor of numerous international academic journals and periodicals. His name was especially associated with the Heidelberger Althistorische Beiträge und Epigraphische Studien (HABES), which he was sole editor from 1986. Alföldy was corresponding member or honorary member of multiple academic societies and academies and a respected member of the Heidelberg Academy since 1978.
Apart from organizations like the Heidelberg Academy, Alföldy also worked at many other German research institutes: the Deutsche Forschungsgemeinschaft and the German Archaeological Institute, as well as at Italian, French, and Spanish facilities for research of classical antiquity.
Hungarian Archaeology and Art History Society, Kuzsinszky Medal, 1965 (the medal could not be awarded at that time because of Alföldy's emigration out of Hungary; it was awarded in 1992)
Centro Segoviano, Premios "Tierra de Segovia: sus hijos y sus obras": Premio Andrés Laguna, 1997
Commemorative insignia of Rome, 1997
Commemorative insignia of the President of the Hungarian Republic "Nagy Imre" for "prominent work in support of the spirit of the Revolution of 1956", 1997
University Medal of the University of Heidelberg, 2006 (for his commitment to international exchange)
Writings
Bevölkerung und Gesellschaft der römischen Provinz Dalmatien. Akadémiai Kiadó, Budapest 1965
Epigraphische Studien. Rheinland-Verlag, 1968
Die Hilfstruppen der römischen Provinz Germania inferior. 1968
Fasti Hispanienses. Senatorische Reichsbeamte und Offiziere in den spanischen Provinzen des römischen Reiches von Augustus bis Diokletian. Steiner, Wiesbaden 1969
Konsulat und Senatorenstand unter den Antoninen. Prosopographische Untersuchungen zur senatorischen Führungsschicht. Habelt, Bonn 1977
Sir Ronald Syme, 'Die römische Revolution' und die deutsche Althistorie. 1983
Römische Sozialgeschichte. 3. Aufl. Steiner, Stuttgart 1984 (Wissenschaftliche Paperbacks. Sozial- und Wirtschaftsgeschichte. Band 8)