All three received conditional discharges after a judge at the City of London Magistrates' Court found them guilty of aggravated trespass, meaning they will receive no punishment unless they commit further offences.
In two separate incidents, Just Stop Oil members Deborah Wilde, 69, Simon Milner-Edwards, 67, and William Ward, 66 ran onto one of the outside courts on July 5th, 2023.
In the first incident, a man and a woman wearing "Just Stop Oil" T-shirts ran onto Court 18 during play and "discharged what is believed to be orange paper petals and jigsaw pieces," said police.
Later, a man ran onto the same court to carry out a similar protest.
The judge said that it was "not in dispute" that each defendant "sprinkled some confetti or tinsel and some jigsaw pieces on to that playing field" and that he "found it a fact" that they were trespassing.
Just Stop Oil wants the UK government to end all new oil and gas exploration and has promised not to let up in its protests until it does so.
Its activists also disrupted the World Snooker Championships, the British Open golf tournament and an international match at Lord's Cricket Ground last year.
