The ex-legspinner was a regular user of cocaine when he introduced his dealer to another man in April 2021.
The 55-year-old knew the quantity of cocaine exchanged was valued at $330,000, but did not know the exact weight after being told the dealer wanted "a brick".
In May 2025, he was convicted of taking part in supplying less than 250g of cocaine and sentenced to a 22-month intensive corrections order and 495 hours of community service.
The former cricketing great launched an appeal against the conviction and sentence in the NSW Court of Criminal Appeal, but his bid was unanimously struck down on Wednesday.
"The appeal is dismissed," Justice Anthony Payne told the court more than a year after the sentence was handed down.
MacGill's barrister Dominic Toomey SC argued the judge erred in determining the exact quantity of drugs the cricketer thought was being exchanged during the deal.
He contended during the appeal the lucrative payment was inconsistent with the finding that MacGill had facilitated an exchange of less than 250g.
MacGill regularly paid his dealer $200 for half a gram of cocaine, the jury was told during the trial.
"It's an (inescapable) truth in this case that at an amount of 250g, a payment of $330,000 would equate to $1320 per gram," Mr Toomey said.
"That is, 3.3 times the price (the dealer) was selling it for."
But it was open for the judge to find the amount of cocaine supplied had been non-specific but considerable, the appeal judges determined.
"It was reasonably open to the sentencing judge to form the conclusion that the amount of $330,000 was settled ahead of time," justices Payne, Belinda Rigg and Helen Roberts found.
MacGill did not receive any of the hefty payment but instead had $1000 of drug debts wiped by his dealer.
The spin bowler was later assaulted in a dilapidated rural shed after his dealer stole two bricks of cocaine in a subsequent drug ripoff.
MacGill was bundled into a car in April 2021 and taken to a home in western Sydney where he was stripped and beaten before being released.
Once viewed as one of the world's top spin bowlers, MacGill is now on JobSeeker while working as a casual cricket coach.
He retired from cricket in 2008 after a career throttled by the sport's greatest legspinner, Shane Warne, who was two years his senior.
MacGill played 44 Tests, claiming 208 wickets at an average of 29.02.
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