Uncial 0313 (in the Gregory-Aland numbering), is a Greek uncial manuscript of the New Testament. Palaeographically it has been assigned to the 5th century.
The codex contains a small text of the Gospel of Mark 4:9.15, on one fragment of the one parchment leaf. The original size of the leaf is unknown; the surviving fragment is 10 by 2 cm.
The text is written in one column per page, and the original number of lines is unknown. The surviving fragment has only 2 lines.
Uncial 0313 is currently housed at the Christopher De Hamel Collection (Gk. Ms 3) at the Corpus Christi College in Cambridge.