From Old English 'cæg' meaning key; an occupational name for a key-maker or keeper.
Key as a given name occupies a fascinating intersection of music, geography, history, and the modern American tradition of single-syllable names with maximum resonance. Its most celebrated namesake is Francis Scott Key, the Maryland-born lawyer and amateur poet who witnessed the British bombardment of Fort McHenry in September 1814 and was so moved by the sight of the American flag still flying at dawn that he wrote the poem that became "The Star-Spangled Banner" — a text that, set to music, would become the United States national anthem in 1931. That single act of patriotic witness attached enormous historical gravity to an otherwise modest surname.
As a given name, Key also resonates in contemporary culture through Keegan-Michael Key, the comedian and actor known for Key & Peele, who has raised the name's profile in popular consciousness. In music, "key" is a foundational concept — the tonal center around which a piece of music is organized — lending the name an artistic, structural connotation. The word itself derives from the Old English cæg, a word of uncertain further etymology, originally meaning a physical key but long extended metaphorically to mean that which unlocks or provides access.
In modern naming, Key functions beautifully as both a standalone given name and as a nickname-as-name — clean, direct, and impossible to misspell. It suits parents attracted to minimal, high-impact names that carry both literary-historical depth and contemporary cool. Its gender neutrality is an additional modern virtue, as it carries no strong gendered association in its short form.