NELLA MARIE LARSEN was born in New York City on April 13, 1891, the second and youngest daughter of a Danish woman, Mary Hansen.Her father was a West Indian chauffeur, but there is no birth certificate to verify either the date and place of her birth or the identity of her father, except through records of other family members. Her half-sister, Anna, whose father was white, was born less than a year earlier. Mary Hansen married Peter Larsen on February 7, 1894; Nella was raised in an all-white household and attended school in the suburbs of Chicago.There is speculation that Nella was removed from the household when she was 9 or 10 years old; in the 1910 census, when Nella was 19, Mary Larsen is recorded as having only one child. After Nella's death, her half-sister remarked that she had not known that she had a sister. The pain and pattern of this enormous rejection led Nella to rewrite her childhood when she became an adult and would reverberate throughout her writing.
Larsen traveled through many educational institutions and in 1915 received a nursing degree from the Lincoln Hospital of Nursing. She was briefly a nurse at Tuskegee Normal and Industrial Institute in Alabama but then returned to New York City, where she worked at Lincoln Hospital and at the Department of Health.She excelled in her profession and was highly regarded by her colleagues, but by 1924 she had begun a new career as a librarian, in charge of children's books at the Harlem branch of the New York Public Library.
In 1919, Larsen married Dr. Elmer S. Imes, a physicist and notorious womanizer. The marriage would end in scandal in 1932, but the couple was part of the 1920s Harlem Renaissance, friends of W. E. B. Du Bois, Jessie Fauset, James Weldon Johnson, Jean Toomer, Carl Van Vechten, and Walter White.In the midst of this period of black artistic creativity and the rise of what was called the New Negro, Larsen began to write fiction. In 1920, as Nella Larsen Imes, she wrote two pieces for The Brownies' Book, a magazine for black children edited by Jessie Fauset: introductory remarks to "Three Scandinavian Games" and "Danish Fun" tell of her childhood spent in Denmark, a fiction Larsen would often repeat. Six years later, she published two short stories for adults that may be characterized as pulp fiction: "The Wrong Man" and "Freedom" appeared in Young's Magazine under the inverted name Allen Semi.