[4] On 5 January 2023, Amorim was appointed as Chief Advisor for Foreign Policy by Luiz Inácio Lula da Silva.

Amorim has a long history of government service, beginning in 1987 when he was appointed Secretary for International Affairs for the Ministry of Science and Technology.

While serving in the Ministry of External Relations, Amorim spent large amounts of time working as an ambassador to the United Nations.

On July 19, 2008, Amorim stirred up controversy by comparing the descriptions used by wealthier countries to characterize the agricultural concessions they were offering during the Doha Round of WTO talks to the work of Nazi propagandist Joseph Goebbels.

[7] In addition, Celso holds a number of honorary positions, including the following: In 2019, Amorim joined the inaugural meeting of the Puebla Group in Buenos Aires, a conference of left-leaning political leaders.