Don Alejandro de la Vega is Diego de la Vega's father, a wealthy landowner commanding respect as part of California's Spanish colonial aristocracy. His fortune stems from managing a large hacienda and agricultural operations, though its specific origins remain undefined. He previously served as Governor, wielding political influence, but later confronts oppressive government officials threatening local stability.

Beneath a stern and self-assured exterior lies a fundamentally compassionate man. He consistently uses his resources and status to aid civilians facing oppression, driven by a deep concern for the community's welfare under military rule.

His relationship with his son Diego is central. He recalled Diego from studies in Spain due to their homeland's turmoil and a desire for familial connection. While loving Diego, he expresses frustration and disappointment over his son's perceived laziness, lack of courage, and disinterest in serious matters. Alejandro openly wishes Diego possessed the noble qualities of the masked vigilante Zorro, whom he admires for defending justice.

Alejandro exhibits notable perceptiveness regarding Zorro's identity. He is among the few who suspects, almost from the beginning, that Diego might be Zorro, despite the stark contrast between his son's foppish persona and the hero's actions. This persistent intuition reveals his insight into Diego's character beneath the facade.

Family and tradition hold great importance for him. He hosts a welcome party for Diego's return, reflecting his social role. Alongside Lolita Prideaux's parents, he nurtures long-standing hopes for a marriage between Diego and Lolita, viewing it as a suitable union of prominent families. He diligently works to preserve the family hacienda and financial security, seeing it as a crucial legacy and responsibility.