John O'Brien is S3 Group'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 six design centers and multiple sales offices globally and is based in S3 Group's headquarters in Dublin, Ireland.

Prior to his appointment as CEO in 2001, O'Brien served as S3 Group's Chief Operating Officer. When first appointed to this position, John consolidated S3 Group'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 Group in 1989. Earlier, he held a series of technology and engineering positions at Plessey Semiconductors in the UK.

Under O'Brien's leadership, S3 Group 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 Group's development of highly valuable technology in its target markets and expand S3 Group'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 recently participated in the Enterprise Ireland 'Leadership for Growth' program at Stanford University. This program lasted for one year and was 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 was one of 29 accomplished and experience leaders who were selected to join the program. John is currently an active member of the Irish Software CEO Forum.