Sébastien de Montessus

Sébastien de Montessus (born 1974) is a French businessman. He was the CEO of Endeavour Mining from 2016 to 2024, until he was sacked following allegations of a multimillion-dollar "irregular payment".

Montessus was born in Paris, and claims to have aristocratic ancestry.

He earned a degree from ESCP Business School in Paris, and started a career as an investment banker. In 2002, he joined the French nuclear power company Areva, rising to head of mining and group deputy CEO. From 2012 to 2016, he was the CEO of La Mancha Group, and joined Endeavour Mining as CEO when La Mancha effectively gained control of Endeavour in 2015.