OVO Energy is an energy supply company based in Bristol. It was founded by Stephen Fitzpatrick and began trading energy in September 2009, buying and selling electricity and gas to supply domestic properties throughout the UK. By June 2017 OVO had 680,000 customers, an increase of 10,000 over the previous year, representing a 2.5% domestic market share.^[1] In November 2018, OVO Energy acquired one of its largest competitors, Spark Energy. Although at first one of over 15 smaller energy companies competing with the Big Six which dominated the market, in January 2020 OVO completed the acquisition of the retail arm of SSE, becoming itself one of the Big Six and the country’s third-largest domestic energy supply company.

The company is British-owned and privately backed. OVO Energy has been supplying gas and electricity to domestic customers since 2009, and to business customers since 2013