The firm, which supplies 5.5 million customers in the UK, echoed rivals British Gas and EDF in blaming the soaring cost of wholesale gas for its decision to raise gas bills by 26% and electricity prices by 16%.
The price rises will come into force from Friday August 22.
Dual fuel customers who take both gas and electricity from E.ON will see their annual bills rise by 22%, or £227, to £1226. This is an average of those paying by monthly direct debit and those who pay bills quarterly.
Graham Bartlett, the managing director of E.ON's retail business, said: "We've tried to keep these increases as low as possible while protecting as many of our customers as we can."
Wholesale gas prices leapt by 14% on Wednesday following a leak on a Norwegian pipeline sparked fears about winter supplies. The pipeline could remain shut until next spring.
E.ON said around 1.4 million of its customers on price protection and fixed tariff products would be unaffected by the higher bills.
British Gas announced another 35% rise for gas bills last month, and 9% for electricity, with rival EDF upping bills by up to 22%.
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