The Wild Free-Roaming Horses and Burros Act of 1971 provides federal oversight and protection for feral horses (wild free-roaming; WFR horses) that inhabit designated areas on public lands in the western United States. The Bureau of Land Management (BLM) estimated in 2019 that over 80,000 free-roaming equids inhabited 29 million hectares on 177 designated herd management areas. This population estimate exceeds the designated appropriate management level of 26,785. To provide BLM managers with insights regarding the U.S. public knowledge and perceptions about the management of WFR horses in the U.S., we surveyed the public using an online survey process. We hypothesized that respondents from the western U.S. would be more knowledgeable of the ecology and management of WFR horses, because of their proximity to most of the WFR horses managed in the U.S. We stratified the U.S. into five regions, with the intent to acquire at least 400 responses from each; we met this quota in four of the five regions (n of southwest = 376). Overall, the U.S. public was unknowledgeable about the ecology of WFR horses and legal management options to control their populations. While there were some associations between region, sex, age, income, and each of our questions, the strength of these associations was very weak. Therefore, demographics may not be useful in predicting the level of knowledge of the U.S. public concerning WFR horses. Our results highlight the need for improved outreach and communication efforts regarding the issues and consequences of free-roaming equid management approaches.