Iarnród Éireann has reported a mean hourly rate gender pay gap of 6.32% in favour of women.
Under new laws, companies with more than 250 staff must report their gender pay gaps in the month of December.
In its report, Iarnród Éireann says that increased representation of women across all roles in the organisation is a key target.
It adds that as female representation in operational roles across train operations and infrastructure management increases, the gender pay gap is likely to narrow in the years ahead.
Just over 11% of Iarnród Éireann's 4,231 employees were women on the reporting date of 19 June 2022 and the company says it has a target of doubling the number of female employees by 2030.
"Our people will better serve our customers and communities if we better reflect those customers and communities, which is why increased representation of women in our workforce is such a priority for Iarnród Éireann," said Iarnród Éireann Chief Executive Jim Meade.
Meanwhile, the Financial Services Union (FSU) has described as "unacceptably high" the gender pay gap reported across the banking sector.
Each of the four main retail banks have now reported their findings with the mean gender pay gap averaging 19.35% across the four main banks and the median averaging 18.71%.
"The numbers reported across all the retail banks are very worrying and deserving of urgent attention," said John O'Connell, General Secretary of the FSU.
"The gender pay gap can best be resolved through a willingness of employers to engage with unions and agree action plans that put this issue as a core objective of their business plan," Mr O'Connell said.
The FSU is calling for a range of measures including greater transparency around pay ranges, more part-time and flexible working arrangements for staff and audits of pay increases to ensure fairness and equality.
Organisations across Ireland have been reporting their gender pay gaps throughout December.
On Monday, RTÉ reported a median gender pay gap of 13.03% in favour of men which reduces to 6.79% when roles with overtime are excluded.
The broadcaster said it has a mean, or average, gender pay gap of 11.55% which reduces to 10% when roles with overtime are excluded.
Dublin City Council has a mean gender pay gap of 4.8%, the ESB reported an average gender pay gap of 10.9% while An Post recently reported a zero gender pay gap for the second year in a row.
The national gender pay gap in Ireland is estimated to be 11.3% according to Eurostat figures from 2019, compared to an EU average of 13%.
