Ros Altmann is taking on the government's new role as business champion for older workers.
Altmann will be tasked with making the case for older workers within the business community and challenging outdated perceptions.
She is a former director-general of Saga and has recently been working as an independent consultant on later life issues.
Pensions minister Steve Webb MP said the move marked the latest step in the government's drive to support over-50s in the UK labour market.
It follows the publication last month of the government's Fuller Working Lives - A Framework For Action report which set out the benefits to individuals, business and the economy as a whole of people aged over 50 staying in work.
Altmann said: "I am so pleased that the government has shown it recognises the importance of encouraging people to stay in the labour market, rather than giving up before they need to.
"This will bring benefits all round - to individuals, to business and to the economy as a whole. A big part of my role is to work with employers to understand the significant benefits of retaining and recruiting older workers.
"I am really proud to be taking on this new role and look forward to championing over 50s in the workplace. This fast-growing section of society has so much experience and talent to offer and could play a vital role in future growth.
"Everyone can benefit from ensuring their skills do not go to waste. I also look forward to challenging some of the outdated and downright inaccurate perceptions of later life workers who still have so much to offer."
Webb added: "In appointing a Business Champion for Older Workers I wanted a powerful voice; someone respected amongst the business community, with a track record of speaking up for consumer rights without fear or favour. In Dr Ros Altmann that's exactly what we have.
"Older workers have a huge amount to bring to any workforce and are a vast, untapped talent in the UK labour market. The business case is compelling and I am delighted that Ros will now be taking a lead in going out and making that case directly to the business community."
According to government statistics there are currently around 2.9 million people aged between 50 and state pension age out of work in the UK.
While the UK employment rate for this age group is around 60% and growing, many other countries achieve rates of around 70% or higher - so there is clearly significant potential for more older people to participate in the labour market for longer, the Department for Work and Pensions said.
It added that demographic changes would also present major opportunities for employers to harness the benefits of taking on older staff, but also pose a serious threat to businesses which continue to believe they can rely solely on a young workforce.
In the next 10 years, there will be 700,000 fewer people aged 16-49 in the UK labour market but 3.7m more people aged between 50 and state pension age.
