A short form of Madison, Madeline, or related names, used as a familiar modern nickname.
Madi most commonly serves as a given name in its own right today, though it springs from a rich pool of antecedents. It functions as a short form of Madison, Madeline, Madeleine, Madisyn, and occasionally Madilyn — names drawn from disparate origins that Madi consolidates into a single, buoyant sound. Madeline and Madeleine trace back to Magdalene, the designation of Mary Magdalene in the New Testament, derived from the Hebrew place name Migdal (tower, meaning a place of elevated significance).
Madison, by contrast, is a patronymic surname meaning son of Matthew that crossed over into given-name use in the 1980s and '90s, partly accelerated by the 1984 film Splash. As a standalone name, Madi carries the infectious energy of its era — it belongs to the generation of clipped, confident girl's names (Lexi, Cali, Bree, Demi) that came to prominence in the late twentieth century and established that names need not be formal to be serious. The three-letter, two-syllable form is particularly suited to the ways names function in contemporary life: easily spelled, naturally shortened already, strong in digital contexts where brevity is an asset.
Madi has also gained literary texture through the beloved children's book series Madeleine by Ludwig Bemelmans, whose spirited Parisian schoolgirl has kept the full form — and all its diminutives — vivid in the imaginations of successive generations. Whether arriving via that golden-haired adventurer or via the boardrooms of Madison Avenue, Madi arrives carrying optimism, capability, and the sense of someone who knows exactly who she is.