Jack Dorsey became Twitter’s CEO after Dick Costolo resigned in 2015.
Costolo stepped down as chief executive in July 2015, and Dorsey returned as interim CEO. Twitter later made Dorsey permanent chief executive. Dorsey had co-founded Twitter and served as its first CEO, but he had left the role in 2008 and later concentrated on Square, the payments company he co-founded.
His return created an unusual dual leadership arrangement because he continued running Square while leading Twitter. Dorsey served as Twitter CEO until November 2021, when Parag Agrawal succeeded him. Dorsey remained Twitter’s chairman for a period after leaving the CEO position.
Dorsey’s second tenure included efforts to improve product growth, expand advertising and address harassment and abuse on the platform. He also oversaw Twitter during major debates about political speech, moderation and platform governance. The 2015 succession is sometimes confused with Dorsey’s original appointment in 2006 or with his later resignation from Twitter’s board in 2022.