Leisa is a variant of Lisa or Elisa, from Elizabeth, meaning God is my oath.
Leisa is a quietly individual rendering of Lisa, one of the great mid-century names in the English-speaking world. Lisa itself began as a diminutive of Elizabeth, the Latinized form of the Hebrew Elisheba — meaning 'my God is an oath' or, in some interpretations, 'my God is abundance.' Elizabeth has been among the most continuously used female names in Western history for two millennia, borne by saints, queens, and literary heroines too numerous to list.
Lisa emerged from the Italian and Spanish diminutive traditions, took hold in English, and achieved remarkable dominance: in the United States it was the most popular girl's name for much of the 1960s. The spelling Leisa — pronounced identically — arose from the same impulse that has always driven parents toward individualization: the desire to give a child a name that is recognizable in sound but distinctive on paper. The variant traces appear in records through the mid-20th century, a period when creative respellings were an active part of naming culture rather than an aberration.
Leonardo da Vinci's Mona Lisa gave the plain four-letter form its most enduring cultural association, and the Beatles' 'Lovely Rita' and Nat King Cole's 'Mona Lisa' cemented Lisa in popular consciousness as a name for a certain luminous femininity. Leisa wears the weight of that heritage lightly. It is, at its core, a name that says: I come from a beloved tradition, but I am specifically myself. That balance — between inheritance and identity — gives it a timeless, human quality that stands apart from both the strictly classical and the purely invented.