Miss Moore said last night she was seeking legal advice to challenge and overturn the disqualification process, which she said had denied her natural justice by not giving her a chance to respond to complaints.
The decision also did not reflect the views of voters at the recent association election, she said.
OUSA president Simon Wilson yesterday confirmed that, after an appeal, Miss Moore had been disqualified.
[comment caption= Should Jo Moore have been disqualified?]Under association rules, the next highest-polling candidate, Edwin Darlow, would become president next year, he said.
Mr Wilson would not give reasons for the decision, or comment on criticism of the appeals process.
A written decision, by the association's independent election arbitrator, Prof Paul Roth, of the university's Law Faculty, was not available for the media yesterday, Mr Wilson said.
A more detailed statement was likely today, he said.
Miss Moore, a commerce student, said she had been stunned to be told at a 1pm meeting at the association office yesterday that she had been disqualified.
She had been unaware that any further appeal had been made and had had no chance to provide any evidence or to make any response to allegations against her, she said in an interview.
Before yesterday's announcement, she had been continuing her induction training as association president-elect after returning officer Kyle Matthews had investigated two earlier complaints against her, and ruled late last month that Miss Moore's recent presidential victory- by 122 votes over the closest of seven other candidates- should stand.
Miss Moore said she understood a complaint that she had been within 20m of a polling facility during voting had been upheld, and it had also been suggested she had overspent the $1000 limit for election campaigning.
She disputed the findings and said she had receipts for all her election spending.
The latest appeals process had breached the principles of natural justice because she had not been advised about it and had been given no chance to provide any evidence on her own behalf, she said.
