Classroom Chaos was a controversial British TV documentary programme, aired on Five, in which a retired teacher under the pseudonym "Sylvia Thomas" returned undercover as a supply teacher after a 30-year teaching gap. She claimed her objective was to show the "chaos" which teachers must deal with in the classroom. With the use of hidden cameras, she filmed chairs being smashed, pupils fighting in class, swearing at teachers by pupils and false accusations by pupils of her touching them. The filming was done using hidden cameras in a button and a briefcase. The documentary showed children aged from 12 to 15 completely ignoring the supply teacher and other staff while they shout, scream, fight, swear, downloading porn and wandering around the classroom at will.

The filming was carried out at 15 ordinary secondary schools in London and the north of England, randomly chosen by the supply agencies she contacted. None of which were considered to be failing by recent inspection reports.