Massumeh Noushin Seyhoun, Professionally known as Massumeh Seyhoun, (Persian: معصومه سیحون;1934–21 May 2010), née Monir Noushin (Persian: منیر نوشین) was an Iranian painter, curator, and gallerist.

[1] Massumeh Seyhoun was born as Monir Noushin in 1934 in Rasht.

She studied at the Faculty of Fine Arts of Tehran, where her teacher was Hooshang Seyhoun, architect, sculptor, painter, who became her husband, and they had two children.

[3][4] When Seyhoun's health started failing in the mid-1990s, she passed control of the gallery to her son Nader.

[3] Her daughter, Maryam, opened the Seyhoun Gallery, Los Angeles, on Melrose Avenue in West Hollywood, an outpost of the Tehran gallery in the United States.