Theodosia Marchant was born in Athens, Greece. She studied law in London and obtained a Bachelor's and Masters in Law. She practiced as a UK and EU registered attorney for several years before relocating in 2013 to Los Angeles with her partner.
In 2019 she had two solo exhibitions in Los Angeles, Domestic Animals | Life in 16 Frames (Fathom Gallery) and The World of Others (Gallery 825). Selected US and international group exhibitions include Hajimemashite (Bridge Mogura Gallery, Tokyo, 2023), Unprecedented Reality (Artual Gallery, Beirut, 2022), The Greatest American Art Form (Court Tree Collective, NY, 2022), 10th Edition of Millerntor Gallery (Curare l Skateboarding x Art, Germany, 2022), I of LA (Mash Gallery, LA, 2020), Powerhouse with Patti Astor (Shockboxx Project, LA, 2019), Out There (Gallery 825+City of West Hollywood, LA, 2019), LA Art Show (bG Gallery 2019), Pulse of LA (SoLA Gallery, 2018) and others. Theodosia has upcoming Beirut, London, and Cyprus solo and group shows. In May 2021, she was a guest speaker at Glendale Community College. Marchant often juries and curates shows for art partner Shockboxx Project Gallery.