Cecily Wilhelmine Ullmann Sidgwick (1854–1934) was a prolific British novelist of the late nineteenth and early twentieth centuries. Over the course of her literary career, she published forty-five novels, writing primarily under the pen names Mrs. Alfred Sidgwick and Andrew Dean. Her body of work is particularly notable for its focus on the Jewish experience in both England and Germany, offering readers a detailed look into the domestic and social lives of middle-class families.
Born in Islington, London, to German-Jewish parents David Ullmann and Wilhelmine Auguste Flaase Ullmann, Sidgwick's background heavily influenced her choice of literary themes. In her writing, she frequently examined the complexities of marriage, cultural integration, and identity. Her novels did not shy away from serious societal issues, regularly addressing topics such as anti-Semitism, the challenges of interfaith marriage, and the tragedy of suicide.
In 1883, she married Alfred Sidgwick, an eminent logician and philosopher who was based at Owens College in Manchester. Her marriage connected her to prominent academic circles, though she maintained a highly active and independent writing career. Sidgwick spent her later years in Cornwall, where she passed away on August 10, 1934, in the village of St Buryan. Today, her novels remain of interest for their historical depiction of Anglo-German Jewish life during a period of significant social transition.