He will have a particular focus to help develop the company's expanding managed estate.
Brakspear's managed estate has nine pubs, including four sites in the Cotswolds as well as Henley-on-Thames, Oxfordshire; Marlow, Buckinghamshire; Mickleham, Surrey; Staines, Middlesex; and Shepherd's Bush, west London. Three more sites are scheduled to open later this year.
Furness-Smith retired this summer from McMullen, the Hertfordshire brewer and pub retailer, where he served almost 20 years as managing director. The company has 85 managed and 35 tenanted pubs.
He previously spent 10 years as retail director of brewer and pub operator Morland. He has also worked for Whitbread, including a stint as a manager of a Beefeater Steakhouse, and spent time in the City and also in the army.
"I've been impressed with what Brakspear has achieved over the past few years, particularly the clear market positioning they have developed for each of their pubs,” said Furness-Smith.
"I like their focus on people and the culture that exists across the business of genuinely putting customers first, and helping good individuals and teams to achieve their potential. The Brakspear managed estate looks set for great things and I look forward to helping the team to develop this side of the business."
Brakspear chief executive Tom Davies said: "Having someone of Peter's calibre to advise and guide us is a tremendous asset and we are delighted to have him on board. His experience over many years in the hospitality industry, particularly at McMullen with its sizeable managed estate, will prove invaluable as we seek to build our own managed business.
Furness-Smith joins Brakspear's existing non-executive directors Ed Turner and Tim Davies.