The school had gone to the High Court seeking approval of its code of conduct, including its uniform regulations, after a row erupted over the suspension of fifth form pupil Grant Stranaghan for failing to comply with hairstyle regulations.
The Rathcoole teenager was suspended for three days in November for refusing to get his hair cut and was later segregated from other pupils on his return to school.
Lawyers for the 16-year-old and another pupil disciplined for the length of his hair had contested the action, claiming that the school's rules sexually discriminated against boys.
However, after a three-day judicial review hearing, the judge said he was satisfied that the school's code was not unlawful.
Mr Justice Weatherup ruled that Grant Stranaghan's human rights had not been breached, but added that he should have been put on detention rather than being segregated from his classmates.
The judge said that as segregation was "not part of the disciplinary policy", a lesser sanction should have been used upon his return to school after his suspension.
"We are obviously pleased that the judge has decided that our code of conduct, including our uniform code, is lawful. This is an important decision, not just for Ballyclare High School, but for all other schools and organisations which operate a uniform code.
"We have been deeply grateful for the huge support which we have received from all quarters throughout this process. We know that the overwhelming majority of our parents and pupils will be pleased and relieved that we can now carry on with the proper business of the school," a statement issued on behalf of the school said.
Speaking to the Newtownabbey Times on Monday, Grant's father, George Stranaghan, confirmed that he is awaiting confirmation from his solicitor regarding the exact wording of the appeal decision and advice on what steps he can take next.
Mr Stranaghan has vowed to appeal against the ruling that his son wasn't discriminated against, vowing to take the case further, including possibly to the European Court of Human Rights.
"If the appeal doesn't work then I am willing to go the whole way for him. We will go as far as we can with this," he commented.
"I am waiting for the school to apologise at the very least. I think we are due an apology after they put him (Grant) in solitary confinement for six weeks," Mr Stranaghan added.
Grant is currently sitting his mock GCSE exams, and his father is waiting to see what action the school is going to take when he returns to classes.
Ballyclare High School's rules on hairstyles do not permit male pupils to grow their hair to a length that reaches their blazer collar.