Antonina Roll-Mecak is a Romanian-born American molecular biophysicist. She is currently the Senior Investigator and Chief of the Unit of Cell Biology and Biophysics at the National Institutes of Health. She holds appointments at the National Institute of Neurological Disorders and Stroke; and at the Biochemistry and Biophysics Center of the National Heart, Lung and Blood Institute. Roll-Mecak is known for her work in understanding cytoskeletal regulation, mechanisms of microtubule dynamics and laying the groundwork for deciphering the complexities of the tubulin code. She is also known for her work on microtubule severing enzymes spastin and Katanin.