Debbie King, Arch Druidess of the Insular Order of Druids in Portsmouth, pictured, was arrested at Fareham Magistrates Court for carrying a five-inch blade.
Miss King was dressed in her regular clothes but handed security officers a bag containing all her Druid accessories, including the sheathed knife known as an athame.
When she went to collect the bag later she was kept waiting for an hour before two police officers arrived and arrested her.
Miss King, 44, said she had the Druid kit with her as she was due to carry out a television interview later in the day, and didn't know if she would have time to return home and collect her belongings after supporting a family member in court.
Miss King, of Furze Lane, Milton, Portsmouth, said: 'It would have the same status as a crucifix to Christians. It represents truth, honour, justice and protection.
'I was told if I signed a disclaimer and gave up the athame I would just be given a caution, but I had to stand my ground.
'If it was just for me I wouldn't mind so much, but it's for all the other pagans who carry a knife – this could create a precedent.'
King Arthur Pendragon, Battle Chieftain of the Council of British Druid Orders, is vowing to fight for Miss King's right to carry her knife.
King Arthur, who was cleared at court in 1996 for carrying his broadsword, said: 'If it goes to court, I'll defend it to the hilt. I think it's ridiculous – we've proved time and time again in court that it's only for ceremonial reasons.'
chris.broom@thenews.co.uk