(February 1, 1925 – December 17, 2005), also known as Sister Mariani, was a Catholic nun and activist in the Philippines who fought against the dictatorship of Ferdinand Marcos.

[1] Dimaranan headed Task Force Detainees of the Philippines, created in the early years of martial law in the Philippines by the Association of Major Religious Superiors of the Philippines to investigate and document human rights abuses.

[1] She became a political detainee in 1973 after she was accused of being a communist.

She was also accused of writing articles against Marcos.

[1][2] Her name is inscribed on the Bantayog ng mga Bayani Wall of Remembrance, a memorial that honors martyrs and heroes who fought the dictatorship.