The Equality Authority is targeting firms who discriminate against older people in job advertisement and restrict access to services such as rental cars or travel insurance based on age.
The authority's chief executive, Niall Crowley, said discrimination based on age already accounted for just over 12 per cent of cases of alleged discrimination under employment equality legislation.
He was speaking at the launch of "Say No To Ageism" week, a campaign organised by the Equality Authority, Health Service Executive (HSE) and National Council of Ageing and Older People. The series of week-long events includes a billboard advertising campaign, new guidelines for the media on reporting, and a number of transport initiatives.
Cases being examined by the authority, meanwhile, include age discrimination in relation to a range of areas including job promotion, access to motor insurance and public sector services.
"False assumptions about older people and their capacity and aspirations can govern decision-making that impacts on them," he said.
"We hope that the week can challenge ageist attitudes, behaviours and will contribute to creating new and improved experiences and situations for older people."
The week was launched by former taoiseach Garret FitzGerald, who yesterday called for the removal of mandatory retirement ages.
"For many professions, being able to continue in work beyond 65 can be life affirming and life enhancing . . . we should recognise the individual capacity of people rather than forcing them into standardised, age-defined behaviour," he said.
Chair of the National Council on Ageing and Older People, Eibhlin Byrne, said society in general needed to address the damaging effects of discriminating against older people.
"The virus of ageism will only be tackled when individuals in the public, private, voluntary, community and other sectors identify ageism in their own attitudes and institutional practices and take the kind of practical steps to eliminate it," she said.
The campaign also aims to promote cultural change and help larger institutions and organisations adapt.
Mr Crowley said institutional changes needed champions to provide leadership in developing age-friendly practices and procedures that enhance their contribution to equality for older people.