Ada Esther Leverson (née Beddington; 10 October 1862 – 30 August 1933) was a British writer who is known for her friendship with Oscar Wilde and for her work as a witty novelist of the fin-de-siècle.
Leverson was born into a Jewish family. Her father was Samuel Henry Beddington, a wool merchant, and her mother's name was Zillah.
She had eight younger siblings, one of whom died in infancy. Her living siblings were named Evelyn, George, Charles, Sybil, Frank, Arthur and Violet. Sybil (who later married David Seligman) had a brief affair and long friendship with Giacomo Puccini. Violet (1874–1962) turned down a marriage proposal from composer Arthur Sullivan and later married author Sydney Schiff.
At 19 Ada married Ernest Leverson (1852–1921) without her parents' consent. The marriage broke up when he moved to Canada in 1905. It has been suggested that her trilogy, The Little Ottleys, is loosely based on her own marriage. Her daughter and biographer, Violet Leverson, married Guy Percy Wyndham in 1923 as his second wife. Her grandson was short story-writer and novelist Francis Wyndham. Ernest Leverson's cousins include actor Darrell Fancourt and, by marriage, actor-playwright Brandon Thomas.
Leverson began writing during the 1890s, as a contributor to Black and White, Punch, The Yellow Book, St. Stephen's Review, Saturday Review, and Referee. She also worked as a drama critic, though when and what she wrote is unknown. Much of her work cannot be identified because she wrote anonymously, because she frequently befriended the people she parodied and critiqued.
She was known as a wit; her writing has been compared to the work of Max Beerbohm and the stories of Saki.