| Adelaide del Vasto | |
|---|---|
| Countess of Sicily Queen consort of Jerusalem | |
 | |
| Born | c. 1075 |
| Died | 16 April 1118 (aged 43) |
| Spouses | |
| Issue | Simon of Sicily Roger II of Sicily |
| House | Aleramici |
| Father | Manfred del Vasto |
Adelaide del Vasto (Adelasia, Azalaïs) (c. 1075 – 16 April 1118) was countess of Sicily as the third spouse of Roger I of Sicily, and Queen consort of Jerusalem by marriage to Baldwin I of Jerusalem. She served as regent of Sicily during the minority of her son Roger II of Sicily from 1101 until 1112.
Her rule occurred between the previous reign of multiple Arabian dynasties and the formal declaration of the Kingdom of Sicily, placing her between two massive shifts in Sicilian identity. Under Adelaide, the economic and social shifts of Norman conquest led to many rebellions and societal tension, which she handled with frightening swiftness.
She was the daughter of Manfred del Vasto (brother of Boniface del Vasto, marquess of Western Liguria, and Anselm del Vasto).
Her paternal grandparents were Teto II del Vasto, and his wife Bertha of Turin, daughter of margrave Ulric Manfred II of Turin.