Zavaleta or Zabaleta is a surname of Basque origin.
[1] The Basques are a people indigenous to areas of northern Spain and southern France, an historical region known as the Basque Country.
Zavaleta (Zabaleta) includes a lexeme ("zabal", 'small square / courtyard' as a noun, according to linguist specialist Koldo Mitxelena) and a suffix ("eta", suffix expressing 'abundance').
The surname Zabaleta is created in the Basque language by combining the root, Zabal, with the suffix, eta, hence Zabal-eta.
The two spellings are interchangeable and represent one single family worldwide.