Kelbie likely comes from a Scottish or English surname/place name related to a farm or settlement by a spring.
Kelbie occupies the frontier between the ancient and the invented, drawing from a cluster of similar names with roots in Old Norse and Scottish place-name traditions. The element *kel-* or *kelby* appears in several Northern English and Scottish place names, generally deriving from Old Norse *kelda*, meaning "a spring" or "a well" — a humble, life-giving source of fresh water that would have been vital to any medieval settlement. Place-name surnames like Kelby and Kelso were formed from such elements and eventually crossed into first-name use, as surnames frequently do in English-speaking cultures.
Kelbie as a given name is largely a modern American development, part of the expansive family that includes Kelby, Kelsey, Kellie, and Kelby. It carries the upbeat, accessible feel of other *Kel-* names while the *-ie* ending softens it into something warmer and more intimate — a diminutive quality that reads as affectionate rather than casual. The name sits comfortably in the South and Midwest United States, where creative respelling and suffix variation are strong naming traditions, and it has appeared with increasing regularity since the 1990s.
What Kelbie offers that its better-known cousins do not is genuine rarity paired with immediate intelligibility. It requires no explanation, mispronunciation is unlikely, and yet a person named Kelbie is unlikely to share a classroom with another. The name has a fresh-air quality — the Old Norse imagery of a spring in a field somehow persisting through the centuries into a contemporary name that still evokes something clean and naturally sourced.