John O'Brien is S3's Chief Executive Officer and a member of the company's Board of Directors. John oversees all strategic and operational aspects of the business, managing four design centers and six sales offices globally and is based in S3's headquarters in Dublin, Ireland.

Prior to his appointment as CEO in 2001, O'Brien served as S3's Chief Operating Officer. When first appointed to this position, John consolidated S3's Europe and US-centric organizations into a unified structure and shifted the company’s strategic focus from a pure services business model to an increasing mixed product and services position. O'Brien joined S3 in 1989. Earlier, he held a series of technology and engineering positions at Plessey Semiconductors in the UK.

Under O'Brien's leadership, S3 has been recapitalized with a recent investment of over $18.5 million in funding from ACT Venture Capital and Enterprise Ireland. This funding into the USA and Asia is being used to accelerate S3's development of highly valuable technology in its target markets and expand S3's business.  

O'Brien has extensive experience in Technology and Market Strategy, Business Development, Project Management, and Corporate Finance. He is an engineering graduate from the University of Limerick, having graduated in 1984 with a Bachelor's Degree in Engineering (B.Eng.). He earned his MBA (1992) from the Smurfit Business School at University College Dublin.

John was recently chosen by the Irish Software Association and Enterprise Ireland to participate in a 'Leadership for Growth' program at Stanford University. This program lasts for one year only and is aimed at developing and enhancing the leadership ambition, mindset and capability of its CEOs to help them create companies that achieve dominant market positions. John is one of 29 accomplished and experience leaders who were selected to join the program. John is also an active member of the Irish Software CEO Forum.