Preventing Child Marriage in Displaced Populations Act This bill directs the President, through the United States' Permanent Representative to the United Nations (U.N.), to push for the U.N. to develop a comprehensive strategy to address the problem of child marriage in U.N.-administered refugee settlements. The strategy shall include a mandate to collect and report data on suspected child marriages, protocols for preventing child marriages, and programs to support and rehabilitate victims of such marriages. The Permanent Representative shall also advocate for the U.N. to (1) examine the relationship between child marriage and violence against girls in all of its research into child marriage, and (2) adopt a standard definition of "child marriage."