Dorsey, who also helms fintech firm Square Inc, will be succeeded by Chief Technology Officer Parag Agrawal.
Here is a timeline of milestones in Dorsey tenure at Twitter:
2006: Typed out the microblogging platform's first post: "just setting up my twttr".
2008: Co-founder Evan Williams took over as CEO after the board pushed Dorsey out. Dorsey assumed the role of chairman.
2013: Twitter went public at a valuation of $31 billion.
2015: Dorsey returned as CEO after Dick Costolo stepped down.
2017: A Twitter employee on his last day deactivated then US President Donald Trump's account which was restored 11 minutes later.
2018: Twitter increased the character limit of tweets to 280 from 140, sparking a mixed reaction in twitterverse.
2020: Activist hedge fund Elliott Management pushed for changes, including the removal of Dorsey as CEO.
2020: Twitter reached an agreement with Elliott to add three new directors for letting Dorsey stay on as CEO.
2021: In the wake of the riots at the Capitol, Twitter permanently suspended Trump's account, with the company citing a risk of further incitement of violence.
2021: Twitter outlined plans in February to attain at least $7.5 billion in annual revenue and 315 million monetizable daily active users, or those who see ads, by the end of 2023.
2021: In March, Dorsey sold his first tweet as a non-fungible token (NFT) - a kind of unique digital asset - for just over $2.9 million.
2021: Former US President Donald Trump in July filed lawsuits against Twitter, Facebook Inc and Alphabet Inc's Google , as well as their chief executives, alleging they unlawfully silence conservative viewpoints.
2021: The company said it had 211 million average monetizable daily active users, as of the three months ended Sept. 30.
2021: Dorsey's net worth is $11.8 billion as of Nov. 29, according to Forbes.