Jack Dorsey

Dorsey was born and raised in St. Louis, Missouri. His father is Timothy G. Dorsey and his mother is Marcia A. Dorsey (née Smith). Jack Dorsey is partly of Italian descent on his mother's side. His father worked for a company that developed mass spectrometers and his mother was a homemaker. He was raised Catholic.

Dorsey attended Bishop DuBourg High School. In his younger days, he worked occasionally as a fashion model. By age 14, he had become interested in dispatch routing. Dorsey enrolled at the University of Missouri–Rolla in 1995 and attended for two-plus years before transferring to New York University in 1997, but he dropped out two years later, one semester short of graduating. He came up with the idea that eventually became Twitter while studying at New York University.

While working on dispatching as a programmer, Dorsey moved to California. In 2000, Dorsey started his company in Oakland to dispatch couriers, taxis, and emergency services from the Web. His other projects and ideas at this time included networks of medical devices and a "frictionless service market". In July 2000, building on dispatching and inspired in part by LiveJournal and by AOL Instant Messenger, he had the idea for a Web-based realtime status/short message communication service.

When he first saw implementations of instant messaging, Dorsey wondered whether the software's user status output could be shared easily among friends. He approached Odeo, which at the time happened to be interested in text messaging. Dorsey and Biz Stone decided that SMS text suited the status-message idea, and built a prototype of Twitter in about two weeks. The idea attracted many users at Odeo and investment from Evan Williams, a co-founder of that firm in 2005 who had left Google after selling Pyra Labs and Blogger.

Noah Glass, Evan Williams, and Biz Stone co-founded Odeo, later renamed Obvious Corporation, which then spun off Twitter, Inc. Dorsey became Twitter's chief executive officer (CEO) when it was founded in 2007. As CEO, Dorsey saw the startup through two rounds of funding by venture capitalists. As the service began to grow in popularity, Dorsey chose the improvement of uptime as top priority, even over creating revenue—which, as of 2008, Twitter was not designed to earn. Dorsey described the commercial use of Twitter and its API as two things that could lead to paid features. His three guiding principles, which he says the company shares, are simplicity, constraint, and craftsmanship.

Dorsey lost his position as CEO in 2008, reportedly for leaving work early to enjoy other pursuits, such as yoga and fashion design. On October 16, 2008, Williams took over as CEO, while Dorsey became chairman of the board. During his time as chairman, Dorsey joined several State Department delegations, including a trip to Iraq in April 2009, led by Jared Cohen. In November, when Iranians took to the streets in the Green Revolution, Twitter was scheduled to conduct maintenance of its site, which would entail temporarily shutting down Twitter's servers. Dorsey responded to a request from Cohen to delay the maintenance so that it would not affect the protests in Iran, because Iranians were using Twitter to communicate and coordinate. Since President Obama had announced that there would be no meddling in Iran, the move sparked controversy. In February 2010, Dorsey was part of another State Department delegation, this time to Russia. In March 2011, he returned to Twitter as executive chairman after Dick Costolo replaced Williams as CEO. In July 2015, Costolo resigned as CEO, with Dorsey assuming the post of interim CEO. He was named permanent CEO in October 2015.

In May 2016, Dorsey announced that Twitter would not count photos and links in the 140-character limit to free up more space for text. This was an attempt to entice new users, since the number of tweets per day had dropped from about 500 million in September 2013 and its peak of 661 million in August 2014 to about 300 million in January 2016.

On November 22, 2016, Dorsey was briefly suspended from his own Twitter account with 3.9 million followers. …

In 2012, Dorsey moved to the Sea Cliff neighborhood of San Francisco.

In 2015, Dorsey said he began his mornings with meditation. In late 2017, Dorsey completed ten days of meditation known as Vipassanā taught by followers of S. N. Goenka. In November 2018, Dorsey went on a birthday Vipassanā meditation trip to Myanmar.

In 2019, Dorsey contributed financially to the campaigns of 2020 Democratic presidential candidates Tulsi Gabbard and Andrew Yang. In 2020, he donated $15 million to 29 mayors pursuing the piloting of guaranteed basic income programs in the United States.

Until 2021, Dorsey applied "world leader" exceptions that enabled Donald Trump to post content on Twitter that would normally be removed or generate sanctions per the platform's rules. In May 2020, some of Trump's tweets received warning labels, and from Election Day 2020, more flaggings were applied to his tweets. On January 6, 2021, after Trump supporters stormed the U.S. Capitol, Twitter applied a 12-hour timeout to Trump's account for violating its Civic Integrity policy. Trump's account was suspended permanently on January 8 based on a review of his posts' content and context. On January 14, Dorsey defended banning Trump but also said it "sets a precedent I feel is dangerous".

In June 2023, Dorsey endorsed Robert F. Kennedy Jr. in his campaign to become the Democratic party nominee in the 2024 United States presidential election.

In 2024, Dorsey tweeted in support of Gaza war protests in the United States, Vietnam war protests, and Iraq war protests.

In October 2025, Dorsey endorsed Kentucky Congressman Thomas Massie for the 2028 Republican Party presidential nomination.

In March 2016, Dorsey fully funded about 600 Missouri public school projects registered at DonorsChoose.

In October 2019, Dorsey donated $350,000 to #TeamTrees, a nonprofit started by YouTubers MrBeast and Mark Rober, that pledged to plant 20 million trees by the end of 2019.

On April 7, 2020, Dorsey announced that he would move about $1 billion of his equity in Square, Inc., just under a third of his total wealth, to Start Small, LLC, and to relief programs related to the coronavirus. He committed to funding COVID-19 relief, girls' education and health, and universal basic income. Dorsey has donated $24 million to over 40 different grantees for relief efforts.

In August 2020, Dorsey donated $10 million to Boston University's Center for Antiracist Research, founded by Ibram X. Kendi.

In May 2021, Dorsey donated $15 million to support relief efforts in India's COVID-19 second wave. The three NGOs were Care ($10 million), Aid India ($2.5 million), and Sewa International ($2.5 million).

In January 2024, Dorsey gave $10 million to the Freedom of the Press Foundation, the largest donation in that organization's history. It followed a $1 million donation he had given in July 2023 in honor of whistleblower Daniel Ellsberg, who had just died.

In August 2026, he pledged to donate $ 1 million to the Omacom Foundation, which “will hold the trademarks, fund the infrastructure, promote the work, and support the open-source projects and developers” used by the controversial Omarchy Linux Project, founded by its also controversial figurehead David Heinemeier Hansson.