Insurance companies claimed compensation, citing the 1886 Riot Damages Act, after a Sony warehouse in Enfield was targeted by arsonists.
The legislation said "damage by riot" should be paid out of police funds.
But the court said the mayor's office - which funds the Met Police - should not pay for loss of profit and rent.
Mr Johnson asked for a Supreme Court ruling following hearings in the High Court and Court of Appeal.
A number of insurance companies had argued the destruction and looting of the Sony warehouse fell into the category for compensation as specified by the Victorian legislation - and they wanted the police to foot the £80m bill.
A High Court judge had ruled the Sony warehouse was damaged on 8 August 2011 during "widespread civil disorder" and the losses had arisen out of damage caused by "persons riotously and tumultuously assembled" and should be paid for out of police funds.
But he decided that there was a limit to liability - and said "consequential losses", including loss of profit and rent, were not "in principle recoverable".
Insurers challenged the decision on the "extent of liability" and the Court of Appeal ruled in their favour, concluding that legislation provided a right to compensation for consequential loss.
But five Supreme Court justices, who heard the case in January, have now published a ruling to overturn that appeal court decision.
They concluded the Riot Damages Act does not "extend to cover consequential losses".
The Sony warehouse was attacked on 8 August 2011 during widespread riots that followed the death of Mark Duggan in Tottenham.
More than 1.5m CDs were destroyed in what lawyers called "the largest ever arson attack in Europe".
Chris Owen, head of disputes at law firm TLT which represented the Met Police, said: "With many claims for consequential loss dependent on the outcome of this case, today's Supreme Court decision will likely save the UK taxpayer upwards of £80m.
"The Supreme Court ruling today has clarified that the compensation payable by the Metropolitan Police is limited to the costs of repairing the damage done to property during the 2011 London riots."
London Mayor Boris Johnson will not have to pay compensation after a warehouse was destroyed in the city's 2011 riots, the Supreme Court ruled.