Guillaume started his career in 2005 at The Boston Consulting Group in New York and then joined Audax Private Equity in Boston. He then joined Mubadala in its Acquisitions Unit, where he focused on the Industrials and Aerospace verticals.
Guillaume joined Tikehau Capital as Head of Investments in 2011. He led TKO’s acquisitions of Salvepar and Duke Street and established the group’s London presence. He then co-headed the Group's Private Equity business from 2015 to 2018. Guillaume serves on Tikehau Capital’s Management Committee and is a member of the Investment Committees of the firm’s Growth Equity, Energy Transition, and Special Operations strategies.