Polyzelus was an Athenian comic poet active during the late 5th and early 4th centuries BCE, a period known as the era of Old Comedy. His exact birth and death dates are unknown. He is recorded as having competed in the City Dionysia, Athens' major dramatic festival, and he won first prize there at least once.

His work survives only in fragments. According to a later Byzantine encyclopedia, he wrote two comedies: Demotyndareus and The Birth of Aphrodite. These titles suggest his plays involved mythological parody, which was a common theme in Old Comedy. The plays themselves are lost, and their content is known only through brief quotations preserved by later ancient authors and scholars.

As a poet of Old Comedy, Polyzelus was part of the same vibrant theatrical tradition as the more famous Aristophanes. His recorded victory shows his work was successful in his own time. Although only fragments remain, his existence and the titles of his plays help modern scholars understand the broader scope and variety of comic production in Classical Athens beyond just the handful of major figures whose works survive in full.