Born in Galesburg, Illinois, Tanning moved to New York City in the 1930s, where she became deeply involved with the Surrealist circle. Her early artistic development was significantly shaped by her exposure to the European Surrealist movement, leading to her breakthrough in the 1940s with works that explored the uncanny and the subconscious.

Her signature style often featured intricate, unsettling compositions involving figures in states of metamorphosis or transition, frequently rendered in oil on canvas. Beyond painting, she expanded her practice into soft sculpture, creating elaborate fabric-based installations that pushed the boundaries of traditional Surrealist form.

Tanning maintained a prolific career that spanned several decades, eventually gaining recognition as a multifaceted artist who also contributed to literature and poetry. Her legacy continues to be examined in major institutional retrospectives that highlight her pivotal role in the development of 20th-century American Surrealism.