Daniel S. Warmenhoven is an American technology executive best known for his long tenure as CEO of Juniper Networks, a leading provider of networking and cybersecurity solutions. Born in 1950, Warmenhoven joined Juniper in 1996 as part of its founding team and became CEO in 1999, guiding the company through its initial public offering in 1999 and subsequent growth into a multi-billion-dollar enterprise. Under his leadership, Juniper expanded its product portfolio in routing, switching, and security technologies, establishing itself as a key competitor to Cisco Systems. He stepped down as CEO in 2014 after 15 years, during which the company's revenue grew from under $100 million to over $4 billion annually, and transitioned to roles on the board of directors and as executive chairman before retiring from active involvement.

Prior to Juniper, Warmenhoven built a robust career in the tech industry. He spent over a decade at Hewlett-Packard (HP) in various engineering and management positions, followed by roles at 3Com Corporation, where he contributed to product development in networking hardware. His early career focused on electrical engineering, reflecting his technical expertise that informed his strategic decisions at Juniper. Warmenhoven's leadership emphasized innovation and market expansion, particularly in high-performance networking for service providers and enterprises. Post-Juniper, he has served on boards of other tech firms and investment committees, leveraging his experience in Silicon Valley's ecosystem.

Warmenhoven's contributions to the technology sector have been recognized through industry awards, and he is credited with fostering a culture of engineering excellence at Juniper. While not deeply involved in public policy or philanthropy on a high-profile scale, his influence in networking standards and corporate governance remains notable among peers.