The 'Heart Skips a Beat' singer reached the financial milestone at the end of 2011, accounts for his company Stanley Entertainment have stated.
However, the earnings only cover his career until December last year, reports The Sun.
His total earnings since appearing on the 2009 series of The X Factor are likely to be much higher by the end of 2012, following his recent tour, supporting One Direction in the US and his second album going double platinum in the UK.
A source said: "Olly is a real grafter – he's worked his socks off since he took part in The X Factor.
"He is constantly juggling working on The Xtra Factor, touring and recording new music, so every penny is hard earned."
> Ten Things About... Olly Murs
Murs was quoted earlier this year as saying he would like to become a millionaire by the end of 2012.
He said: "Am I a millionaire yet? That will hopefully come this year. The difference with me is that I am very conscious of my money and I look after it."
Olly Murs recently announced plans to release the Flo Rida duet 'Troublemaker' on November 18.
His third studio album Right Place Right Time will follow on November 26.