Mariana Wright Chapman (March 14, 1843 – November 9, 1907) was an American social reformer and women's rights activist.

[5][2] As her children grew older and the family responsibilities lessened, she became an active worker in the Hicksite Society of Friends,[3] serving for several years as a trustee of its school and as a member of its philanthropic committee.

[2] While all movements for the betterment of humanity received her support, her most active work was in the direction of prison reform and equal rights for women.

She was also a member of the Woman's Auxiliary of the Civil Service Reform Commission, and was instrumental in establishing the Friends' Equal Rights Association.

[3] She was one of the chief supporters for the bill which appointed matrons in police stations, there to serve the needs of women prisoners.