The Countess of Derby usually refers to the wife or widow of an Earl of Derby, such as:

• Margaret Peverell, Countess of Derby ({{circa|1144}}–1154), English noblewoman
• Margaret Clifford, Countess of Derby (1540–1596), great-granddaughter of King Henry VII of England
• Alice Spencer, Countess of Derby (1559–1637), English noblewoman
• Elizabeth de Vere, Countess of Derby (1575–1627), English noblewoman and daughter of Edward de Vere, 17th Earl of Oxford
• Charlotte Stanley, Countess of Derby (1599–1664), English noblewoman famous for her role against the siege of Lathom House
• Elizabeth Smith-Stanley, Countess of Derby (1753–1797), English peeress
• Elizabeth Farren, Countess of Derby ({{circa|1759}}–1829), wife of Edward Smith-Stanley, 12th Earl of Derby
• Mary Catherine Stanley, Countess of Derby (1824–1900), English grande dame and political hostess
• Emma Caroline Smith-Stanley, Countess of Derby (died 1876), wife of Edward Smith-Stanley, 14th Earl of Derby
• Alice Stanley, Countess of Derby (1862–1957), wife of Edward Stanley, 17th Earl of Derby

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