Maria Serena Encarnacion Icasiano Diokno, also known as Maris, is a Filipino historian, academic, and former government official best known for having served as chair of the National Historical Commission of the Philippines (NHCP) and as a high-ranking official of the University of the Philippines (UP) system. She graduated UP magna cum laude and earned a PhD in African and Oriental studies at the University of London in 1983. Diokno succeeded fellow historian Ambeth Ocampo as chairperson of the NHCP on April 7, 2011. She resigned from her position on November 29, 2016 in response to the burial of former president Ferdinand Marcos at the Libingan ng mga Bayani in Taguig, Metro Manila.