William Gaillard was senior adviser to the president of UEFA, Michel Platini, from 2009 to 2015, and previously served as communications and public affairs lead from 2003.
During his tenure, he oversaw all external communications and media activities and managed a variety of political issues for football's governing body in Europe.
This included social responsibility initiatives and efforts towards the eradication of racism and discrimination in football.
Gaillard joins from BCW Brussels, where he advised clients on all aspects of sports strategic communications. He was also senior adviser to the president of The International Centre for Sport Security until 2016.
He brings more than 20 years of experience in the sports sector across Europe, The Middle East and the US.
“We’re thrilled to have William on board. With his decades of experience advising the biggest sports and international organisations, William will no doubt strengthen our sports communications capabilities across the world,” Portland chief executive Mark Flanagan said.
“William’s arrival will make a significant contribution to Portland's growing international sports practice and help to develop it in new ways.”
Gaillard is also currently on the executive board of FARE (Football Against Racism in Europe) and the advisory board of Supporters Direct Europe.
He said: “A new endeavour in a career is always an exciting challenge. Being a senior adviser at Portland is doubly so: a new, dynamic international environment and an outstanding group of communications professionals with whom to work.”