An Egyptian court banned on Monday all April 6 activities inside Egypt and ordered the confiscation of their headquarters.
A plaintiff had filed a case against the group, accusing them of engaging in practices that distorts the image of the Egyptian state.
The verdict can be appealed.
The co-founder of the youth movement, Ahmed Maher, was sentenced to three years in prison towards the end of last year for protesting without permit.
April 6 played a significant role in the January 25 uprising that toppled Hosni Mubarak in 2011.