Bord Gáis Energy is to follow Electric Ireland and Airtricity with residential electricity price hikes from 15 October.
It says the 4.8% increase will add more than 50 euro to the average electricity bill, annually.
In addition to the changes, the Commission for Energy Regulation has approved an increase to the PSO levy of €9.67 for all providers from 1 October.
Bord Gais says this will mean that the average annual electricity bill will now be €1,149 from 15 October, up from €1,088 annually.
The company says the increase is due to an increase in the wholesale cost of gas and higher transmission and distribution charges recently announced by the Commission for Energy Regulation (CER).
The company says that it regrets having to introduce the price increase.
It says that the decision is driven by factors beyond their control such as a weakening euro and increasing international wholesale prices and network charges.
Airtricity and Electric Ireland have also announced increases in electricity charges since the beginning of September.
The Chairperson of the Commission for Energy Regulation has said he regrets approving an 8.5% price increase in gas provided by Bord Gaís.
Dermot Nolan said he had no choice due to increases in the wholesale price of gas.
Speaking on RTÉ's Today with Pat Kenny, Mr Nolan also said it appeared that other companies are "copycatting" increases at Bord Gáis, once they are sanctioned by the commission.