Andrew Munday from Northamptonshire admitted six counts of fraud by false representation and three counts of money laundering.
An accountant with high-profile clients such as singer Rita Ora and World Cup-winning rugby player Matt Dawson has been jailed for more than five years, after he committed a £3.35m fraud.
Andrew Munday, 38, caused a loss of nearly £2.4m to Rita Ora's company, during a fraud campaign lasting seven years.
Dawson's company suffered losses of around £1.08m after Munday took money from their accounts and placed it in his own.
The married father-of-two from Moulton in Northamptonshire has been sentenced to five years and eight months in prison, after he admitted six counts of fraud by false representation and three counts of money laundering.
Judge Rupert Mayo told Northampton Crown Court: "The individuals who trusted you with their bank sign-in details and therefore trusted you with their hard-earned wealth have been emotionally harmed by the abuse of trust which you perpetrated."
The court heard how Munday used his profit to finance a gambling addiction and live a "lavish lifestyle", with exclusive membership at Tottenham, as well as buying football memorabilia - including signed Paul Gascoigne shirts.
Munday siphoned £1.6m from Ora's company into his own bank account, and caused a total loss to the firm of £2,390,747 whilst he was an accountant at Blue Cube Business Ltd, which no longer exists.