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Block Inc

Financial TechnologyFounded 2009
Reviewed by Swet Parvadiya
Company data updated: October 2026

Founders

Who Founded Block?

Jack Dorsey, Jim McKelvey · Founded 2009 · HQ today: Oakland, California

Who founded Block?

Block was founded by Jack Dorsey, Jim McKelvey in 2009. It is now led by Jack Dorsey.

Founders
Jack Dorsey, Jim McKelvey
Founded
2009
Headquarters
Oakland, California
Number of founders
2
Current CEO
Jack Dorsey (since 2009)
Where was Block founded?
Block was founded in San Francisco, California in 2009.
When was Block founded?
Block was founded in 2009.
Who started Block?
Block was founded by Jack Dorsey and Jim McKelvey.
How old is Block?
Block is 17 years old as of 2026.

Founding Story

In 2009 Jim McKelvey, a St. Louis glass artist, lost a $2,000 sale because he could not accept the buyer's American Express card. He mentioned it to Jack Dorsey, who had once worked for him and had recently been pushed out as Twitter's chief executive. With engineer Tristan O'Tierney they built a reader that turned a card swipe into an audio signal a phone could read through its headphone jack, and launched Square with published flat pricing and sign-up in minutes instead of a bank merchant account, credit checks and terminal rental.

Jack Dorsey

Co-founder 2009

Background

Jack Dorsey was born on November 19, 1976, in St. Louis, Missouri. As a teenager he wrote dispatch-routing software and worked for Jim McKelvey's St. Louis business. He studied at Missouri University of Science and Technology and New York University without graduating. He co-founded Twitter in 2006 and was its first chief executive until 2008, returned as executive chairman in 2011, served as chief executive again from 2015 until November 2021, and left its board in 2022. He is an outspoken bitcoin advocate.

Role at Block Inc

Dorsey co-founded Square in 2009 with Jim McKelvey after McKelvey lost a glass sale he could not take by card, and has run the company ever since: through the 2015 IPO, the rise of Cash App, the December 2021 rename to Block, the Afterpay purchase and, in February 2026, a cut from more than 10,000 employees to just under 6,000 that he tied to AI. His title is Block Head and Chairman. Between 2015 and 2021 he was also Twitter's chief executive, an arrangement investors repeatedly questioned until he left Twitter to focus on Block.

Education: Bishop DuBourg High School. Jack Dorsey was born in 1976.

Jim McKelvey

Co-founder 2009

Background

Jim McKelvey was born in 1965 and grew up in St. Louis, Missouri. He studied at Washington University in St. Louis, ran a printing and publishing business where a teenage Jack Dorsey worked, and became a professional glass artist. In 2013 he co-founded LaunchCode, a St. Louis nonprofit that trains people for technology jobs.

Role at Block Inc

McKelvey's lost $2,000 glass sale is Square's origin story. He worked with Dorsey and engineer Tristan O'Tierney on the first reader and the flat-pricing business model, and later wrote 'The Innovation Stack' (2020), which explains how Square survived copycats including Amazon's short-lived card reader. He remains a Block director: shareholders voted on his re-election as a Class II director at the June 16, 2026 annual meeting, for a term running to 2029.

Education: Ladue Horton Watkins High School. Jim McKelvey was born in 1965.

Block Inc: CEO & Leadership History

Full timeline →

Alyssa Henry

Seller Lead, then Chief Executive of the Square business

2014 – 2023

Joined from Amazon in 2014 as seller lead and became chief executive of the Square business when the parent was renamed Block in December 2021. She built Square from a card reader into a suite of seller software, banking and loans, and left in October 2023, when Jack Dorsey took over the role as 'Square Head'.

Jack Dorsey

Co-Founder, Block Head and Chairman (Chief Executive)

2009 – Present

Has led Square and Block since 2009: the 2015 IPO, the growth of Cash App, the 2021 rename to Block, the Afterpay purchase, bitcoin projects such as Bitkey and Proto, and the February 2026 cut to just under 6,000 employees. Since Alyssa Henry left in October 2023 he has also run the Square business directly.

Keep researching Block

Who Founded Block? FAQ

Who founded Square?

Jack Dorsey and Jim McKelvey, in February 2009 in St. Louis. Engineer Tristan O'Tierney helped build the first reader.

How did the idea for Square start?

McKelvey, a glass artist, lost a $2,000 sale because he could not accept an American Express card, and told Dorsey, who had once worked for him.

How did the first Square reader work?

It plugged into a phone's headphone jack and turned the magnetic stripe swipe into an audio signal the app could read.

Who invested in Square early?

Khosla Ventures led the Series A, followed by Sequoia Capital, Kleiner Perkins, a round including Citi Ventures and Starbucks, and a Series E with Goldman Sachs and GIC. Visa made a strategic investment in 2011.

Is Jim McKelvey still involved with Block?

Yes, as a director; shareholders voted on his re-election at the June 2026 annual meeting for a term to 2029. He co-founded the LaunchCode nonprofit and wrote 'The Innovation Stack' (2020).

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Content is for informational purposes only. Not financial advice. Data sourced from SEC filings, annual reports, and public records. See our full disclaimer and methodology.