Grace Knowlton (1932 – 4 December 2020) was an American sculptor and photographer who was known for her outdoor sculptures.

In 1981 she received a master's degree in art from the Columbia University Teacher's College.

[1] In the 1960s Knowlton was working in ceramics, and found that she had the urge to close up the openings in the tops of the vessel forms she was producing.

This led her to the concept of creating entirely closed spherical sculptural forms.

Later she learned welding to produce structural armatures for the interiors to support the weight of these materials.