Meaning of the surname Chávez
Chávez is a Portuguese surname of the from a place type meaning "from Chaves". It is one of the 50 most common surnames in Mexico. The link to llaves (keys) on the family arms is folk etymology. Twenty-ninth in Mexico.
About this meaning. The etymology is uncertain or the popular reading is folk etymology. The page gives the best-supported explanation.
Taken from a town, region, or landscape feature in Spain, or later in Mexico: Castillo (castle), Rivera (riverbank), Navarro (from Navarre), Ibarra (Basque valley).
In Mexico a person carries two surnames, the father's and then the mother's, so Chávez appears as either half of a pair: Chávez García, López Chávez. Read how the two-surname system works.