Fulham had argued that the Frenchman had breached his contract by, amongst other things, paying over the odds for certain players during his time in charge at the club.
"I consider that the defendant has behaved properly and conscientiously in his dealings with Fulham and did not act dishonourably," the judge of the case said after the verdict.
A statement issued on behalf of Tigana after the case read: "I am very happy at the decision of the High Court.
"The club made untrue and unfounded allegations against me in an attempt to justify its refusal to honour its contractual obligations towards me, and I am pleased that the judge has decisively rejected these, as did the employment tribunal previously.