Bank of Ireland said its gender pay gap stands at 24.2% as it becomes the first Irish bank to publish such figures in its first gender pay gap report.
This report highlights the percentage difference between what men and women are paid on average in the organisation, irrespective of roles or levels.
Bank of Ireland said there is no sector comparison available yet in Ireland as proposed legislation has not yet been enacted.
But it compares with about 30% for firms within the UK financial services sector where gender pay gap reporting has been in place since 2017.
Bank of Ireland said a major contributor to the gender pay gap is imbalance at senior levels in the bank.
For this reason, the bank in 2018 announced a target to establish 50:50 gender balance in appointments to senior management and leadership by 2021.
Bank of Ireland said it made 44% senior female appointments in 2019, up from 38% when the target was introduced in March 2018.
Today's report also highlights a range of other actions underway across the organisation to improve the gender pay gap.
These include providing career development and leadership programmes for its female workers to increase representation at senior levels, and rolling out more flexible ways of working across the organisation.
About 3,500 of Bank of Ireland's staff are now working flexibly, which can include working from home or from dedicated hubs, closer to where they live, cutting down time spent commuting.
Francesca McDonagh, Bank of Ireland's group chief executive, said the bank has a gender pay gap because it has fewer women in senior roles than men.
"I'm focused on taking action to close the gap as soon as we can," the CEO said.
"That's why we completed a comprehensive group-wide analysis of our gender data, which helps us understand the scale of the issue and allows us track our progress in a transparent and accountable way," she said.
"That's important, because as we all know "what gets measured gets done", she added.
We want to make progress on this issue, and I'd encourage other companies in Ireland to research their own position and publish their gender pay gap findings," Ms McDonagh said.
"Through collective action and more transparency we'll make faster progress, and we'll also change the culture of business in Ireland in a very positive way," she added.