Tweed had been a prominent figure in the Harryville Chapel protest in the late ’90s over restrictions placed on Orange marches.
Yesterday, a spokesperson for the Orange Order said: “Mr Tweed’s conviction automatically terminates his membership of the Institution.”
He had been suspended from the Orange Order during the trial.
Tweed, who has been a councillor in Ballymena since 1997, remains suspended from the TUV.
It remains unclear, however, how Tweed’s seat in the council will be filled, though a by-election is not expected.
Yesterday, a spokesperson for the local authority said: “Council has learned of the media reports that Cllr Tweed has been found guilty of a number of offences.
“We will be considering this matter in conjunction with the relevant electoral legislation; however, no final decision can be made on the matter until the exact sentence is known.”