Variant of Lacy, from a Norman French surname meaning from Lassy in Normandy.
Lacie is a softened, modern spelling of Lacey, which traces its roots to the Norman French family name 'de Laci,' referring to a place in Normandy — likely derived from a Gallo-Roman personal name or possibly from 'laissé,' meaning a boggy woodland clearing. The de Lacy family were among the most powerful Norman lords who accompanied William the Conqueror to England in 1066, and the surname subsequently spread across the British Isles, leaving place names in England, Ireland, and Wales. As a given name, Lacey (and its variants) emerged in the twentieth century, riding the wave of surnames-as-first-names that reshaped English naming conventions.
It became especially popular in the United States and United Kingdom through the 1980s and 1990s, assisted in part by its soft, feminine sound and the association with lace — the delicate textile — which lent it a romantic, almost Victorian sensibility without requiring the full commitment of a Victorian name. The Lacie spelling in particular softens the name further, replacing the hard 'e' ending with a more visually gentle form. It tends to appeal to parents who want something that feels pretty and approachable rather than formal.
In pop culture, the name appeared in various TV dramas of the early 2000s, cementing it as a name that felt youthful and warm. Today Lacie occupies a comfortable niche — familiar without being overused.