One-in-five racist incidents reported happened on public transport
Some 240 racist incidents were reported to a leading rights group last year - an increase of more than 10%.
The Immigrant Council of Ireland said almost one third occurred in the workplace, one fifth on public transport, 40% of the victims had a Muslim background and one third were African.
Experts working with the group said they fear less than half of incidents are reported to gardai.
Its report for 2015 also found one third of the racist attacks were verbal abuse, almost one quarter involved discrimination and 13% involved violence.
The numbers were released as part of a new #StopRacism campaign encouraging people to report racism when they see or hear it.
The publicity drive is being run by the Immigrant Council, the National Transport Authority and public transport companies with ads being put up this month on Dublin Bus, Iarnrod Eireann, Bus Eireann, Transdev, Local Link bus services and regional taxi operators.
Brian Killoran, chief executive of the Immigrant Council, said: "Racist incidents are under-reported, which makes it difficult to assess and tackle racism where it occurs."
Campaigners claimed that 700% more racist incidents, not including sectarianism, are recorded by the Police Service of Northern Ireland than by the Garda.
Mr Killoran said in the four years that an anti-racism awareness campaign has run on public transport there has been an increase in the number of racism reports.
In 2014 there were 217 reports of racism to the Immigrant Council.
The latest report from the European Network Against Racism Ireland revealed 165 reports of racism were made to its iReport.ie system from July to December last year.
The data included 37 serious offences which involved 25 reports of assault, 13 serious threats to harm or kill and 23 incidents committed by strangers.
"It was notable that 20% of reported incidents occurred on public transport. While public transport in Ireland is safe and inclusive, like all public spaces it is not immune to negative behaviours of this nature," Mr Killoran said.
As part of the new campaign ads will be put up at more than 2,000 sites including bus, train and tram networks with the focus on celebrating diversity and urging people to report racism to firstname.lastname@example.org.
Sergeant Dave McInerney, head of the Garda racial and intercultural office, said: "We encourage anyone who experiences or witnesses incidents they perceive as racist to come forward, report it and seek support."
Anne Graham, chief executive of the National Transport Authority, said: "The Proclamation of the Irish Republic, which was declared outside the GPO 100 years ago, contains an intrinsic focus on equality and dignity. We would like to see these ideals better reflected in the Ireland of today."