Isabella FitzRoy may refer to:

Isabella FitzRoy, Duchess of Grafton (née Bennet, 1668–1723), mother of Charles FitzRoy, 2nd Duke of Grafton Isabella Seymour-Conway, Countess of Hertford (née FitzRoy), daughter of Charles FitzRoy, 2nd Duke of Grafton

See also Izo FitzRoy (Isobel FitzRoy, born 1985), English musician