Electric Ireland is set to increase residential electricity prices by 6.2% and residential gas prices by 8% from August.
The company said the increases were in direct response to sustained increases in wholesale energy prices.
It is estimated that today's price hike will add €56 onto the average annual electricity bill and €55 onto the average annual gas bill.
In February, the company increased electricity prices by 4% but its gas prices remained the same.
"It has been a very difficult decision to make, but the wholesale costs required to supply electricity and gas are continuing to rise," Niall Dineen, Head of Residential Markets, Electric Ireland commented
He also said that Electric Ireland continues to give a 5% discount to customers experiencing financial hardship, through prepayment meters and via its household budget scheme.
SSE Airtricity also recently increased their energy prices.
Eoin Clarke, Managing Director of Switcher.ie, said that consumers should brace themselves for similar moves from other suppliers.
"This spells bad news for cash-strapped consumers. Household energy prices rose across the board just last winter, but today's announcement - which comes hot on the heels of a price hike from SSE Airtricity - suggests that there's still more to come," he said.
He advised people to shop around for their energy needs, adding that an average dual fuel customer switching from typical standard tariffs to the cheapest deals on the market can save up to €342 on their energy bills every year.