The fencing of protected areas (PAs) is highly controversial, and much remains unknown about the associated financial, ecological, and social impacts. We surveyed experts on 63 fenced and 121 unfenced PAs across 23 African countries to assess the advantages and drawbacks of fencing. Where fences exist, they are largely supported and widely viewed as effective at demarcating PA boundaries and mitigating human-wildlife conflicts. However, most fences were insufficiently funded, which limited their ability to contain conflict-prone species like elephants and lions. Fences were also frequently vandalised and caused numerous conflicts with local communities. We documented for the first time the distribution of and support for fencing in PAs across Africa. While fencing is largely limited to Southern Africa and East Africa, support for fencing is greatest in West Africa and is associated with high human and livestock densities, and high threats from bushmeat harvesting, livestock encroachment, and logging.