A coated steel product including a base steel, and a coating layer containing a Zn—Al—Mg alloy layer disposed on a surface of the base steel, in which the coating layer has a predetermined chemical composition, the coated steel product including dendrite-shaped MgZn2 phase having a surface roughness Sa of 50 nm or less on a surface of the Zn—Al—Mg alloy layer, an area ratio of the dendrite-shaped MgZn2 phase having a surface roughness Sa of 50 nm or less being from 30% to 80% within a region of an observable field of view of 5 mm2, and among the dendrite-shaped MgZn2 phase having a surface roughness Sa of 50 nm or less, a number of dendrite-shaped MgZn2 phase having an area of 0.1 mm2 or more being from 5 to 100 within a region of an observable field of view of 25 mm2.