Uncial is a majuscule script commonly used from the 3rd to 8th centuries CE by Latin and Greek scribes. Early forms are characterized by broad single stroke letters using simple round forms taking advantage of the new parchment and vellum surfaces, as opposed to the angular, multiple stroke letters which are more suited for rougher surfaces, such as papyrus. In the oldest examples of uncial, all of the letters are disconnected from one another, and word breaks are typically not used.

As the script evolved over the centuries, the characters became more complex. Specifically, around 600 CE, flourishes and exaggerations of the basic strokes began to appear in more manuscripts. Ascenders and descenders were the first major alterations, followed by twists of the tool in the basic stroke and overlapping. By the time the more compact minuscule scripts awoke circa 800 CE, some of the evolved uncial styles formed the basis for these simplified, smaller scripts. Uncial was still used, particularly for copies of the Bible, tapering off until around the 10th century.

The word, uncial, is also sometimes used to refer to manuscripts that have been scribed in uncial, especially when differentiating from those which have been penned with minuscule. Some of the most noteworthy Greek uncials are:

The Petropolitanus is considered by some to contain optimum uncial style. It is also an example of how large the characters were getting.

Modern calligraphy usually teach a form of evolved Latin based uncial hand that would probably be best compared to the later, 7th to 10th century examples, though admittedly, the variations in Latin uncial are much wider and less rigid than Greek. Modern uncial has borrowed heavily from some of the conventions found in more cursive scripts, using flourishes, variable width strokes, and on occasion, even center axis tilt.