West was born in Boston on June 2, 1907, to Isaac Christopher West, an emancipated slave who later became a successful businessman, and Rachel Pease Benson, one of 22 children. West reportedly wrote her first story at the age of 7. At age 14, she won several local writing competitions.

In 1926, West tied for second place in a writing contest sponsored by Opportunity, a journal published by the National Urban League, with her short story "The Typewriter". The person West tied with was future novelist Zora Neale Hurston.

Shortly before winning, West moved to Harlem with her cousin, the poet Helene Johnson. There West met other writers of the Harlem Renaissance, including Langston Hughes, Countee Cullen, and the novelist Wallace Thurman. Hughes gave West the nickname of "The Kid", by which she was known during her time in Harlem.

West's principal contribution to the Harlem Renaissance was to publish the magazine Challenge, which she founded in 1934 with $40. She also published the magazines successor, New Challenge. These magazines were among the first to publish literature featuring realistic portrayals of African Americans. Among the works published were Richard Wright's groundbreaking essay "Blueprint for Negro Writing," together with writings by Margaret Walker and Ralph Ellison.

After both magazines folded because of insufficient financing, West worked for the Works Progress Administration's Federal Writers' Project until the mid-1940s. During this time she wrote a number of short stories for the New York Daily News. She then moved to Oak Bluffs on Martha's Vineyard, where she wrote her first novel, The Living Is Easy. Published in 1948, her novel was well received critically but did not sell many copies.

In the four decades after, West worked as a journalist, primarily writing for a small newspaper on Martha's Vineyard. In 1982 a feminist press brought The Living Is Easy back into print, giving new attention to West and her role in the Harlem Renaissance. As a result of this attention, at age 85 West finally finished a second novel, titled The Wedding. Published in 1995, the novel was a best-seller and resulted in the publication of a collection of West's short stories and reminiscences called The Richer, the Poorer. Oprah Winfrey turned the novel into a two-part television miniseries, The Wedding .

West died on August 16, 1998, at the age of 91. At her death, she was one of the last surviving members of the Harlem Renaissance.