Of that total, 28 million are child refugees who fled conflict, states the UNICEF report, "Uprooted: The growing crisis for refugee and migrant children." An additional 20 million are child migrants who left their homes in search of better lives.
The report defines a child as any person below the age of 18. Although a migrant can be a refugee, the term refugee is specifically used to note people fleeing persecution.
"Some move with their families and others are alone; some have planned their journeys for years while others must flee without warning," states the report, which was published on Wednesday.
The UNICEF report aims to highlight the rising number of young victims of conflict and the dangers faced by those displaced.
It cites recent examples of child victims, including Alan Kurdi
, the three-year-old Syrian boy who was found drowned and face down on a Turkish beach; and Omran Daqneesh
, the five-year-old Syrian boy who sat shell-shocked in an Aleppo ambulance after his family's home was bombed in an airstrike.
"Every child that has suffered, died, is a reminder of this huge challenge that we face," Justin Forsyth, deputy executive director of UNICEF, told CNN. "Every one of them deserves our help."
More than 50% of refugees are children
Children account for more than half of all refugees fleeing conflict, the report states. Nearly half of those children come from just two countries -- Syria and Afghanistan.
What's more, the number of children fleeing alone is on the rise. In 2015, an estimated 100,000 unaccompanied children filed for asylum in 78 countries, the reports says. That's a threefold increase over 2014.
UNICEF is calling on governments to do more to protect and help displaced children, including protecting them from exploitation and violence; ending the detention of those who seek asylum; keeping families together; and giving them access to education, health care and other services.
Parents facing 'terrible decisions'
The number of child refugees has jumped by 75% in the past five years, the report states, spurred by new and ongoing conflicts. Today, 1 of every 200 children is a refugee.
"In some places, like Eritrea and northern Nigeria the children are fleeing violence and conflict -- their parents are almost sending them ahead of them because its safer to flee than it is where they are," Forsyth said.
"Often parents are judging that their children would be safer to move than to stay put and that's a terrible decision," he added.
Although boys and girls make up an equal share of displaced children, the threats facing them are different. Boys are more at risk of recruitment by armed groups, while girls are more vulnerable to sexual violence, the report states.
Forsyth recounted to CNN the example of a young Nigerian girl who had been abducted by traffickers after fleeing the terrorist group Boko Haram
. She was locked in a basement prison in Libya and raped repeatedly, before being sold into sexual slavery in Italy, he said.
"All of these children, whether they're fleeing Central America and gang violence or war in Africa or from Syria are threatened by traffickers and smugglers and they desperately need our protection and our help in getting an education and a future," Forsyth said.
Children face disadvantages and discrimination
Displaced children, particularly refugees, are also at a huge disadvantage when it comes to education, the report states. Refugee children are five times more likely to be out of school than non-refugee children -- and those who do manage to attend classes are far more likely to experience discrimination.
Outside of school, the risk of xenophobic attacks is disproportionately high. The report states that "in Germany alone, authorities tracked 850 attacks against refugee shelters in 2015."
The number of refugee and migrant children is rising. There were twice as many child refugees under the U.N.'s mandate in 2015 than there were in 2005, UNICEF reports. As for migrant children, their proportion within the global population has remained at a steady 1%, but the absolute number continues to increase along with the global population.
"In the last few years we have seen huge numbers of children being forced to flee their homes, and take dangerous, desperate journeys, often on their own," said Lily Caprani, UK deputy executive director of UNICEF. "Children on the move are at risk of the worst forms of abuse and harm and can easily fall victim to traffickers and other criminals."