In 2015-16, private elementary and secondary schools in the United States enrolled 4,903,596 students, according to the National Center for Education Statistics' "Characteristics of Private Schools in the United States: Results From the 2015–16 Private School Universe Survey."
Of those, 78.2 percent—3,834,293 students—attended private schools with a religious orientation. By far, the religion affiliated with the most students is Roman Catholicism. Nearly half of those attending a religious private school in the United States in 2015-16 were enrolled in a Catholic school.
Here are the 10 religious denominations whose schools accounted for the most students in 2015-16.