Phil Harrison's professional career began in 1989 when he started working as a graphic artist for several games for the Oric 1 and later switched focus to game design. Soon after, Harrison began working for System 3, a computer game developer based in London, UK which was founded in 1984 by Mark Cale. Like many in the 1980's 8-bit era, Harrison took his first steps in the video game industry programing for the Commodore 64, taking code he would find in magazines and putting them into the system.
Three years later, Phil Harrison made what will arguably be the biggest career move of his life when he joined Sony Electronics Publishing Ltd as Director of Product development in 1992. In 1993, a new subsidiary of Sony Computer Entertainment Inc arose, Sony Computer Entertainment Europe, and Harrison was reassigned to head of third party and software development for the PlayStation which launched in the region in 1995.
Four years after joining Sony, Harrison moved across the Atlantic to Sony Computer Entertainment America as Vice President to manage third party and licensee relations, product strategy and research and development. Harrison returned to Sony Computer Entertainment Europe four years later in November of 2000. He would take over as the head of the regions development division responsible for the Sony internal studios and the third party developers creating PlayStation 2, PlayStation Portable and eventually PlayStation 3 products, later becoming Sony Worldwide Studios.
In February 2008, Harrison announced his resignation as President of Sony Worldwide Studios after 14 years with the company.
Harrison describes his career with Sony as "the defining journey of my life," where he became renowned within the industry for the first public real time demonstrations for the PlayStation 2 and PlayStation 3 hardware with the now famous "Yellow Rubber Duck" demos.
On March 3, 2008, Infogrames SA announced Phil Harrison the company's President. Harrison's responsibilities will include reinforcing Atari's franchise portfolio in order to boost publishing activity, overseeing development of packaged and online games and bringing in world-class design and development talent to strengthen the company's studio capabilities.
As of May 29, 2009, Infogrames officially changed it's name to Atari and at the same time, announced Harrison's role change from President to Non-executive Director of the Group.
In April 2010 Phil Harrison resigned from his position on the Atari board to join London Venture Partners, a venture capital firm based in the UK.
It was announced on March 12, 2012 that Phil Harrison joined Microsoft as the head of Microsoft Games Studios Europe.
On April 17, 2015 Harrison had confirmed his departure from Microsoft.