Donald Thomas Valentine (June 26, 1932 – October 25, 2019) was an American venture capitalist best known as the founder of Sequoia Capital. Over several decades he helped build the modern venture capital model by concentrating on high‑growth technology firms in the United States and mentoring founders during their formative years. His role in shaping Silicon Valley investing led peers and journalists to call him a leading figure — often described as a "grandfather of Silicon Valley" and an influential early practitioner of the industry’s practices. grandfather of Silicon Valley

Career and institutional legacy

Valentine founded Sequoia Capital in the early 1970s and established a firm model that combined aggressive early-stage investments with hands-on guidance. Sequoia under his leadership became known for backing technology companies that went on to become major industry players. The firm’s approach emphasized concentrated portfolios, founder support, and a willingness to back risky technical ventures before they had proven market traction. Many later venture funds adopted similar structures and incentive models.

Investment style and principles

Valentine’s reputation rested as much on his judgment as on the set of practical principles he applied when evaluating opportunities. His process typically considered:

  • Founder quality and resilience — the team’s drive and ability to execute.
  • Product and engineering differentiation — technology that could create durable advantage.
  • Market opportunity — a path to large, addressable markets.
  • Operational support — active involvement to help scale sales, hiring, and strategy.

Notable influence and examples

While venture capital is collective, many observers credit Valentine with getting Sequoia to back early software, hardware, and networking firms that helped define the personal computing and networking eras. Sequoia investments over time included companies that became household names across computing, enterprise software, and infrastructure. His belief in founder‑led, technology‑driven enterprises contributed to the rise of Silicon Valley as a global technology cluster. His focus remained on technology companies in the United States throughout his career. technology companies in the United States

Legacy and passing

Beyond financial returns, Valentine influenced the culture and language of venture investing: how startups are evaluated, how investors work with founders, and how early capital can shape industries. He remained a respected voice in the community until his death on October 25, 2019 in Woodside, California at age 87. Obituaries and remembrances highlighted both the firms he helped build and the many investors and entrepreneurs who regarded him as a mentor and exemplar.

His career left a lasting imprint on venture capital practice and on the companies that received his early support, and his methods continue to be studied by investors and founders alike.