Adoboli, 34, had his application for permission to challenge his 2012 conviction rejected at the Court of Appeal in London.
"The case was in truth overwhelming and the applicant can have no complaint," judge Brian Leveson said in announcing the decision of three judges.
"We have no doubt that his convictions are unassailable."
The Ghanaian-born banker was jailed for seven years for fraud by abuse of position for losing the Swiss bank's money, and four years for a second count of the same offence, to run concurrently.
The Court of Appeal judges also rejected his application to appeal against what he claimed was his "manifestly excessive" jail sentence.
During Adoboli's trial, he claimed senior managers were fully aware of his activities and encouraged him to take risks to make profits for UBS.
But prosecutors said that in a bid to boost his bonuses and chances of promotion, Adoboli exceeded his trading limits, failed to hedge trades and faked records to cover his tracks.
The tactics initially paid off, but as the financial crisis took hold, Adoboli's deals went bad.
The court heard had that at one point the privately-educated son of a former United Nations official was at risk of causing UBS, Switzerland's largest bank, losses of $12 billion.