Over 25 schools have launched School Students Against War.
Representatives of around 25 schools participated in the event at Marchmont Community Centre in London, which was supported by the Stop the War Coalition (StWC).
The discussion focused on how young people can campaign to build schools not bombs, cut war not public services, tackle Islamophobia and reject military presence in the country's schools.
The group said: "This government is determined to push through cuts that will hit school students hard. The 735 planned new schools are not going to be built. That means tens of thousands of school students forced to learn in crumbling classrooms that are long overdue for replacement.
"Our education is being put on the line to save money.
"The war in Afghanistan is costing £5bn each year.
"Over 77 per cent of Brits are opposed to the war, but the government stubbornly continues to send our troops to die and spend our money blowing apart Afghanistan and slaying women and children."
StWC convener Lindsey German, who addressed the meeting, told the Star: "It has been a very positive event. It's great to see young people showing that there is a new generation who are very angry about the war and other issues."