Maria Luiza Ribeiro Viotti (born 27 March 1954) is a Brazilian diplomat and the current Ambassador of Brazil to the United States.

She held several positions within the Ministry of External Relations, including:[1] Viotti served as Counselor at the Brazilian Embassy in La Paz, Bolivia, from 1993 to 1995,[1] and from 1985 to 1989, Viotti served as a First Secretary at the Brazilian Mission to the United Nations, when she started to specialize in the UN System.

Being a close friend of several Permanent Representatives for decades; having played an important part in assuring the stability and conciliation of political forces in Afghanistan; and having long worked for human rights advances and social development in the poorest countries, she was the Brazilian favorite.

"As a multidimensional threat, terrorism must be addressed from a holistic approach that takes into consideration the diversity of its underlying causes.

From 2016, Viotti served as Under-Secretary for Asia and the Pacific at the Brazilian Ministry of Foreign Affairs, where she had special responsibility for work on BRICS.