Pichette who joined Twitter's board of directors in 2017, earlier previously served as Google's CFO from 2008 till 2015.
"Given the strength and depth of Twitter's management team and Board, we believe that now is the right time to evolve our governance structure in-line with best practices," Pichette said in a filing to the US Securities and Exchange Commission (SEC) on Tuesday.
Pichette will take over from Omid Kordestani who will remain on Twitter's board.
"Omid has been a valued member of our executive management and brought important leadership and stability to the team over the past five years. We are pleased to demonstrate our commitment to good governance and be in the position to make this important change," Pichette added.
Kordestani will receive compensation in accordance with the programmes applicable to non-employee directors as described in Twitter's definitive proxy statement filed with the Securities and Exchange Commission on April 15.
"I have seen firsthand the significant changes Twitter has undertaken to strengthen and stabilize its leadership structure to achieve long-term sustainable growth and feel confident that I can now step back from my active role as executive chair," said Kordestani.