Nationwide staff earning less than £35,000, which is around 61 percent of the 18,000-strong workforce, are in line for the £1,200 bonus.
The building society's move follows on from other British lenders, who have given their staff one-off sums to help cope with soaring prices.
These include HSBC, Barclays, Lloyds, NatWest and the UK arm of Santander.
Debbie Crosbie, chief executive officer at Nationwide, said: "The months ahead will be worrying for many people and we’re always considering new ways to help our members.
"But rising prices affect our colleagues too and that’s why we’re providing this additional support."
Nationwide Building Society will pay more than 11,000 of its staff £1,200
Paul Faith
Liz Truss and Rishi Sunak are both hoping to take over as Conservative Party leader
PA
It comes as Britain finds itself in a crippling cost-of-living crisis.
Last week, figures from the Office for National Statistics (ONS) confirmed that the economy contracted by 0.1 percent between April and June.
Health was put down as the "biggest reason" behind the contraction as the test and trace and vaccine programmes were wound down.
Retailers were also hit hard, despite the Queen's Platinum Jubilee celebrations providing a brief period of respite.
Amid warnings from the Bank of England that the UK might enter recession later this year, the country's leading politicians remain divided on how best to deal with the crisis.
With the Tory leadership race ongoing, and Prime Minister Boris Johnson essentially serving a lame-duck term for the next few weeks, Britain finds itself without decisive direction within Number 10.
Rishi Sunak has said he is prepared to dig out up to £10billion to soften the impact of October's energy price rise, while his plan to scrap VAT on energy will reduce bills for every household by £200.
But rival Liz Truss is only "considering" such a move, as she builds a campaign around cutting taxation and "putting spades in the ground".
Today, Labour's Sir Keir Starmer set out a £29billion emergency plan to stop energy bills rising over winter.
He says his plans are a direct response to a “national economic emergency” which have left millions of families across the country fearing how they will cope.
But despite the initial popularity of his proposals, Sir Keir's pledge was questioned by the Institute for Fiscal Studies (IFS).
IFS director Paul Johnson even described Sir Keir's plan as an "illusion".