Yeung, 54, had denied five charges of money-laundering between January 2001 and December 2007, totalling $93million.
District Court Judge Douglas Yau said Yeung had lied about how he made his money and exaggerated the amount of profit generated by his hair salon business.
"I find the defendant not a witness of truth. I find that he is someone who is prepared to, and did try to, lie whenever he saw the need to do so," said Judge Yau.
Yeung, who was dressed in a dark suit and striped tie, will be sentenced on Friday morning.
The businessman and other investors bought into Birmingham City in 2007 and acquired the rest in 2009.
Last month, Yeung resigned from parent company Hong Kong-listed Birmingham International Holdings Ltd (BIHL) while he awaited the verdict.
A week later, the indebted parent said it was selling a 12 per cent share in its UK subsidiary for HK$45m ($5.8m) to a little-known Chinese advertising firm.
Yeung was arrested in June 2011, when trading in shares of the English second-tier football club's parent was suspended.
They resumed trade on February 7 and have risen 39 per cent since then.
A statement from Birmingham's acting chairman Peter Pannu read: "I regret to inform all supporters and staff of our beloved club that Birmingham City F.C's former president and benefactor, Carson Yeung, was today convicted of all charges he faced following a protracted period of legal proceedings.
"I'd like to reassure all supporters and staff that today's verdict will have no impact on the day-to-day operations at the football club.
"Birmingham International Holdings Limited, the holding company, shall continue to support the football club under the leadership of the group's new chairman, Mr Cheung Shing, and will work to raise further investment to support Birmingham City F.C. going forward."