Which American art movement is Georgia O'Keeffe most closely associated with?

Georgia O'Keeffe is most closely associated with American modernism.

American modernism describes the broad movement in which artists rejected strict academic conventions and explored new ways to represent modern life, perception, and form. O'Keeffe became one of its most prominent American figures through sharply simplified shapes, intense color, and compositions that could approach abstraction.

Her subjects included flowers, skyscrapers, shells, bones, and desert landscapes. Although many viewers classify individual works in different ways, O'Keeffe is not generally categorized as a Pop artist or as an Abstract Expressionist. Her career began before Abstract Expressionism became dominant, and her work retained a distinctive, controlled approach to form. The label American modernism best covers the varied phases of her long career.