A handwriting style that employed large, rounded, and separated capital letters. Generally, there was no word separation, and there were few accents or punctuation marks. The term can also be used of a manuscript written in this style. This writing style was commonly used by copyists to produce Greek Bible manuscripts between the fourth and the ninth centuries C.E.

The most important uncial manuscripts are written on parchment, and these include the following: Codex Sinaiticus, Codex Alexandrinus, Codex Vaticanus, Codex Ephraemi Syri rescriptus, and Codex Bezae Cantabrigiensis. Because of their age and quality, Greek uncial manuscripts are considered to be the most valuable of all witnesses to the texts of the Septuagint and the Christian Greek Scriptures.