Adelaida is the Spanish and Portuguese form of Adelaide, from the Germanic Adalheidis, which means "of noble kind" or "nobility", from adal, noble, and heid, kind or sort. Saint Adelaide, a 10th-century empress, spread the name across Europe, and the Spanish form is a long-standing favorite in Mexico and the Philippines. In the United States Adelaida ranked number 4652 in 2000, climbed to number 2068 in 2024 and sits at number 2647 in 2025 with 65 girls.