Provided is an iron-based soft magnetic powder that may be used in producing a dust core having a low iron loss. The iron-based soft magnetic powder has a crystallinity of 10% or less, volume-based median circularity (C50) of 0.85 or more, and when heated to 400° C. at a heating rate of 3° C./min and held at 400° C. for 20 min in a nitrogen atmosphere, then allowed to naturally cool to room temperature, number density of Cu clusters in the powder of 1.00×103/μm3 or more and 1.00×106/m3 or less, and average Cu concentration of the Cu clusters of 30.0 at % or more.