The wellbeing of single-parent families is a vitally important issue for the United States. Half or more of the children growing up in the U.S. today will spend some, and in some cases all, of their childhood in a single-parent family. This report compares U.S. single-parent families with single-parent families in 16 other high-income countries. We find that U.S. single-parent families are the worst off. They have the highest poverty rate. They have the highest rate of no health care coverage. They face the stingiest income support system. They lack the paid-time-off-from-work entitlements that in comparison countries make it easier for single parents to balance caregiving and jobholding. They must wait longer than single parents in comparison countries for early childhood education to begin. They have a low rate of child support receipt. U.S. single parents have both above average employment rates and above average poverty rates. High rates of low-wage employment combined with inadequate income support explain the paradox of high poverty despite high employment. The comparison high-income countries are Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Ireland, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom (U.K.). These countries have a per capita gross national income above $30,000 and a population of at least several million. Except when a data source omits some of the comparison countries, we report on all of them.