Provided are a high-strength steel sheet, which is suitable as a material of automotive parts, and a method for producing the high-strength steel sheet. In the high-strength steel sheet, the C content is 0.15% or less, the area ratio of ferrite is 8% to 45%, the area ratio of martensite is 55% to 85%, the proportion of martensite grains adjacent to only ferrite grains in the entire microstructure is 15% or less, the average crystal grain sizes of ferrite and martensite are each 10 μm or less, and the area ratio of ferrite grains having a size of 10 μm or more to all the ferrite grains included in a portion of the steel sheet which extends from 20 to 100 μm below the surface thereof is less than 5%.