The number of people aged 65 and over has risen by 85,000 in a decade to almost 900,000, while those under the age of 14 have dropped by 53,000, according to the 2011 Census.
Scotland's older age group represents 17% of the population, with those in the younger bracket representing 16%.
Germany has witnessed a similar trend, with 21% aged 65 and over and 13% aged up to 14. Slovenia is even closer to Scotland with a 17%-14% split. However, Ireland has more younger people, with 21%, than the older group (12%).
Charities and politicians warned that early Government action is needed to stop the cost of caring for the country's senior citizens from bursting the public purse.
Wider service budgets are being squeezed tighter as the total population hit an all-time high of 5.29 million.
Councils have demanded a massive policy rethink as the debate over free personal care further intensified with the release of figures on older people.
MSPs were recently warned that universal benefits available to all pensioners north of the Border may lead to conflict between the generations.
Colin Mair, chief executive of the Improvement Service, a partnership between local authority chief executives and council umbrella body Cosla, said in September that the current older generation appeared to "hit it seriously lucky" with free education and good pensions, which may feed resentment among the young.
Lord Sutherland, the architect of the free personal care scheme, recently cast doubt on his policy and warned the Scottish Government not to cut "better-value" support to voluntary organisations.
In contrast, the latest Census showed that apart from the baby boom years of the 1960s, the number of children has steadily fallen, and halved in 100 years.
MSPs said that as it is revealed the number of people aged over 80 has risen by 20% since the last Census in 2001 – and by eight times since 1911 – Scotland has a "real crisis" ahead. Charities said the value to the community of older people is underestimated and good policies on free care can minimise the need for high-cost hospital and residential care later.
Doug Anthoney, of Age Scotland, said older people can boost society, helping thousands by taking on roles as volunteers, carers, consumers, employees and cultural contributors, but too many find life marred by ill-health.
He said: "Services for older people need to respond to this challenge with a sustained emphasis on prevention.
"This should include acknowledgment that policies such as free personal care and concessionary travel can, by supporting the wellbeing and independence of older people, minimise the need for high-cost hospital and residential care and so deliver long-term savings to the public purse."
John Downie, of the umbrella group the Scottish Council for Voluntary Organisations, added: "Excellent work is already happening. This needs to be better supported and replicated elsewhere but the uncertainty surrounding welfare reform, and proposed cuts including the benefits cap, will seriously impact on progress in this area."
Scottish Tory health spokesman and deputy leader Jackson Carlaw MSP said: "Our ageing population is going to bring huge challenges to our health and social care services.
A Labour spokesman said: "A growing population is to be welcomed but these figures also underline that in common with other European countries we face a demographic time bomb."
Peter Johnston, of the Convention of Scottish Local Authorities, the umbrella body for councils, said: "It is clear that we need to better understand the impact and value of public policy choices and weigh
these against the cost to the public purse. The funding of care is not yet as strained as it appears to be south of the Border, but it is definitely becoming more difficult.
A Scottish Government spokesman said the Census figures confirmed that more people in Scotland are living for longer. "We recognise that this is good news, but that it also brings challenges in terms of the way we plan for, organise and deliver our health and social care services," he said.
It is thought the number of pensioners will swell by 551,200 by the year 2035.