In an open letter addressed to the victims of the Boko Haram kidnappings, the 17-year-old Pakistani teenager, who survived a Taliban bullet in her head and is now based in Birmingham, criticised the global community for failing to help free the 219 schoolgirls kidnapped a year ago.
"In my opinion, Nigerian leaders and the international community have not done enough to help you," she wrote to mark the one-year anniversary of the incident which shocked the world.
Malala's letter, described as "a message of solidarity love and hope", comes as events, including marches, prayers and vigils, were being held to mark the girls' 12 months in captivity.
The Boko Haram militants caused global outrage after abducting the girls from Nigeria's north-eastern Chibok town.
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"We cannot imagine the full extent of the horrors you have endured. But please know this: we will never forget you," said Malala, who has campaigned vigorously on the issue.
In Nigeria, campaign group - Bring Back Our Girls - has launched a week of events encouraging people to remember the girls ahead of the first anniversary of their abduction today.
The UN children's agency, UNICEF, said the abduction of the schoolgirls from Chibok was "only one of the endless tragedies being replicated on an epic scale across Nigeria and the region".
Boko Haram, which means 'Western education is forbidden', launched a rebellion in 2009 and seeks to impose a caliphate on Nigeria - Africa's largest and religiously mixed nation.
Malala, who has written of her own experiences at the hands of Taliban in her native Pakistan, was nearly killed by the armed group in October 2012 for campaigning for girls' right to education.