A high-strength steel sheet comprising: an element composition containing, by mass%: C: 0.17% or more and 0.35% or less; Si: 0.001% or more and 1.2% or less; Mn: 0.9% or more and 3.2% or less; P: 0.02% or less; S: 0.001% or less; Al: 0.01% or more and 0.2% or less; N: 0.010% or less; and optionally one or more of Sb: 0.001% or more and 0.1% or less; B: 0.0002% or more and less than 0.0035%; Nb: 0.002% or more and 0.08% or less; Ti: 0.002% or more and 0.12% or less; Cu: 0.005% or more and 1% or less; Ni: 0.005% or more and 1% or less; Cr: 0.01% or more and 1.0% or less; Mo: 0.01% or more and less than 0.3%; V: 0.003% or more and 0.5% or less; Zr: 0.005% or more and 0.20% or less; W: 0.005% or more and 0.20% or less; Ca: 0.0002% or more and 0.0030% or less; Ce: 0.0002% or more and 0.0030% or less; La: 0.0002% or more and 0.0030% or less; Mg: 0.0002% or more and 0.0030% or less; and Sn: 0.002% or more and 0.1% or less, the balance being Fe and unavoidable impurities, wherein: relative to a whole microstructure of the steel sheet, a total area fraction of one or two of bainite containing carbide grains having an average grain size of 50 nm or less and martensite containing carbide grains having an average grain size of 50 nm or less is 90% or more; and an average number of inclusions having an average grain size of 5 μm or more that are present in a section perpendicular to a rolling direction is 5.0/mm 2 or less. an element composition containing, by mass%: C: 0.17% or more and 0.35% or less; Si: 0.001% or more and 1.2% or less; Mn: 0.9% or more and 3.2% or less; P: 0.02% or less; S: 0.001% or less; Al: 0.01% or more and 0.2% or less; N: 0.010% or less; C: 0.17% or more and 0.35% or less; Si: 0.001% or more and 1.2% or less; Mn: 0.9% or more and 3.2% or less; P: 0.02% or less; S: 0.001% or less; Al: 0.01% or more and 0.2% or less; N: 0.010% or less; and optionally one or more of Sb: 0.001% or more and 0.1% or less; B: 0.0002% or more and less than 0.0035%; Nb: 0.002% or more and 0.08% or less; Ti: 0.002% or more and 0.12% or less; Cu: 0.005% or more and 1% or less; Ni: 0.005% or more and 1% or less; Cr: 0.01% or more and 1.0% or less; Mo: 0.01% or more and less than 0.3%; V: 0.003% or more and 0.5% or less; Zr: 0.005% or more and 0.20% or less; W: 0.005% or more and 0.20% or less; Ca: 0.0002% or more and 0.0030% or less; Ce: 0.0002% or more and 0.0030% or less; La: 0.0002% or more and 0.0030% or less; Mg: 0.0002% or more and 0.0030% or less; and Sn: 0.002% or more and 0.1% or less, the balance being Fe and unavoidable impurities, wherein: relative to a whole microstructure of the steel sheet, a total area fraction of one or two of bainite containing carbide grains having an average grain size of 50 nm or less and martensite containing carbide grains having an average grain size of 50 nm or less is 90% or more; and an average number of inclusions having an average grain size of 5 μm or more that are present in a section perpendicular to a rolling direction is 5.0/mm 2 or less. Sb: 0.001% or more and 0.1% or less; B: 0.0002% or more and less than 0.0035%; Nb: 0.002% or more and 0.08% or less; Ti: 0.002% or more and 0.12% or less; Cu: 0.005% or more and 1% or less; Ni: 0.005% or more and 1% or less; Cr: 0.01% or more and 1.0% or less; Mo: 0.01% or more and less than 0.3%; V: 0.003% or more and 0.5% or less; Zr: 0.005% or more and 0.20% or less; W: 0.005% or more and 0.20% or less; Ca: 0.0002% or more and 0.0030% or less; Ce: 0.0002% or more and 0.0030% or less; La: 0.0002% or more and 0.0030% or less; Mg: 0.0002% or more and 0.0030% or less; and Sn: 0.002% or more and 0.1% or less, the balance being Fe and unavoidable impurities, wherein: relative to a whole microstructure of the steel sheet, a total area fraction of one or two of bainite containing carbide grains having an average grain size of 50 nm or less and martensite containing carbide grains having an average grain size of 50 nm or less is 90% or more; and an average number of inclusions having an average grain size of 5 μm or more that are present in a section perpendicular to a rolling direction is 5.0/mm 2 or less. relative to a whole microstructure of the steel sheet, a total area fraction of one or two of bainite containing carbide grains having an average grain size of 50 nm or less and martensite containing carbide grains having an average grain size of 50 nm or less is 90% or more; and an average number of inclusions having an average grain size of 5 μm or more that are present in a section perpendicular to a rolling direction is 5.0/mm 2 or less.