To provide a soft magnetic alloy or the like, from which a magnetic component having a good temperature property of core loss can be obtained. The soft magnetic alloy includes Fe. The soft magnetic alloy includes a crystallite, and an amorphous phase existing around the crystallite. A total area ratio of the crystallite in a cross section of the soft magnetic alloy is 40% or more and less than 60%. An average thickness of the amorphous phase is 3.0 nm or more and 10.0 nm or less. A standard deviation of a thickness of the amorphous phase is 10.0 nm or less.