Jack Dorsey is a pioneering entrepreneur and technologist best known for co-founding Twitter (now X) in 2006 and Square (now Block, Inc.) in 2009. Born in 1976 in St. Louis, Missouri, Dorsey dropped out of New York University to pursue his interests in dispatch routing software and urban infrastructure, which laid the groundwork for his innovative ideas in real-time communication and mobile payments. As Twitter's inaugural CEO from 2006 to 2008 and again from 2015 to 2021, he scaled the platform into a global force for information sharing, amassing over 330 million monthly active users at its peak under his leadership. Dorsey's achievements extend far beyond social media; he transformed the fintech landscape with Square, introducing a simple card reader that democratized payments for small businesses worldwide. The company, rebranded as Block, Inc. in 2021 to reflect its broader ecosystem including Cash App, Tidal, and Afterpay, has grown into a multi-billion-dollar enterprise listed on the NYSE under BLOCK INC CLASS A. A vocal advocate for Bitcoin and decentralized finance, Dorsey has invested personally in crypto initiatives and launched TBD, Block's Web5 platform, to advance open-source financial tools. As Block Head at Block, Inc., Dorsey steers the company's vision toward economic empowerment through technology, overseeing innovations in payments, bitcoin mining via Spiral, and creator economy tools. His leadership has driven Block's market cap to over $40 billion, emphasizing simplicity, resilience, and financial inclusion, while he continues to influence the tech industry through his roles on boards like Bluesky and his philanthropy via the Start Small initiative.