Nicanor was a Greek grammarian who lived during the 4th century BCE, a period when the systematic study of language and texts was developing. He is identified as a specialist in grammar, but no details about his life, such as his origin or teachers, have survived.

He is credited with authoring a single, pioneering treatise titled On Punctuation (Περὶ στιγμῆς). This work is now lost, but it is referenced by later historical sources. According to these accounts, Nicanor's treatise was the first known specialized study on punctuation. It introduced a system of eight marks designed to guide the proper recitation and interpretation of poetic texts, including the works of Homer.

Nicanor's significance lies in his early, technical contribution to textual scholarship. Modern scholars view his work as an important step in the history of philology, representing a move toward standardizing how ancient texts were read aloud and understood. Although his specific system was later expanded upon by grammarians in the Hellenistic period, such as Aristophanes of Byzantium, Nicanor is remembered as a foundational figure in the study of punctuation.