Louisa Mary Anne Julia Harriet Montagu, Countess of Sandwich (née Lady Louisa Lowry-Corry; 3 April 1781 – 19 April 1862) was an Irish noblewoman and society figure, who in 1804 became the wife of George Montagu, 6th Earl of Sandwich. She posed for artists including Sir Thomas Lawrence, and her bust was sculpted by Antonio Canova.