A postdoctoral researcher or postdoc is a person professionally conducting research after the completion of their doctoral studies (typically a PhD, DSc, DBA, DEd., DTh.). The ultimate goal of a postdoctoral research position is to pursue additional research, training, or teaching in order to have better skills to pursue a career in academia, research, or any other field. Postdocs often, but not always, have a temporary academic appointment, sometimes in preparation for an academic faculty position. They continue their studies or carry out research and further increase expertise in a specialist subject, including integrating a team and acquiring novel skills and research methods. Postdoctoral research is often considered essential while advancing the scholarly mission of the host institution; it is expected to produce relevant publications in peer-reviewed academic journals or conferences. In some countries, postdoctoral research may lead to further formal qualifications or certification, while in other countries, it does not.

Postdoctoral research may be funded through an appointment with a salary or an appointment with a stipend or sponsorship award. Appointments for such a research position may be called postdoctoral research fellow, postdoctoral research associate, or postdoctoral research assistant. Postdoctoral researchers typically work under the supervision of a principal investigator. In many English-speaking countries, postdoctoral researchers are colloquially referred to as “postdocs”.