Provided are a ferrite powder capable of maintaining a high withstand voltage even when used in a resin composition having high magnetic properties and electrical resistivity and a high filling ratio, and a method for producing the same. A ferrite powder composed of spherical ferrite particles, wherein the ferrite powder contains iron (Fe): 55.0-70.0 mass % and manganese (Mn): 3.5-18.5 mass %, the ferrite powder containing more than 0.0 mass % to 7.5 mass % α-Fe2O3, and the ferrite powder has a volume average particle size (D50) of 15.0 μm or less.