Pseudo-Justin is the name given by modern scholars to the unknown author or authors of several early Christian texts. These works were composed in the 2nd century CE but were incorrectly attributed for centuries to the famous Christian philosopher and martyr, Justin Martyr. The true identity, location, and life details of this anonymous writer are completely lost to history.

This author wrote in the tradition of early Christian apologetics, a form of writing that defended the faith against pagan critics and internal heresies like Gnosticism. According to modern scholars, attributing new works to a respected figure like Justin was a common practice at the time, used to lend authority to theological arguments. The writings of Pseudo-Justin therefore reflect the ongoing intellectual efforts to define Christian doctrine and its relationship to Greek philosophy in the decades after the apostolic age.

The surviving works attributed to Pseudo-Justin include treatises such as the Exhortation to the Greeks, On the Monarchy of God, and the Exposition of the True Faith. The authorship of the eloquent Epistle to Diognetus is also highly disputed and often connected to this corpus. The significance of these texts lies in their window into early Christian thought beyond the most famous Church Fathers. Scholars study them to trace the development of ideas like monotheism and Logos theology, and to understand the common literary practice of writing under a respected name to bolster a work's influence.