A high-strength hot-dip galvanized steel sheet having tensile strength of 1100 MPa or more and a chemical composition comprising, in mass%, C:0.08 to 0.35%, Si: 0.01 to 3.0%, Mn: 2.0 to 4.0%, P: 0.010% or less, excluding 0, S: 0.002% or less, excluding 0, Al: 0.01 to 1.50%, and B: 0.0005 to 0.010% and further comprising one or more selected from Mo: 0.03 to 2.0% and Ti: 0.010 to 0.10%, and optionally one or more selected from Nb: 0.005 to 0.20%, V:0.005 to 2.0%, Cr: 0.005 to 2.0%, Ni: 0.005 to 2.0%, Cu: 0.005 to 2.0%, Ca: 0.0002 to 0.0050%, REMs: 0.0002 to 0.0050%, Sn: 0.001 to 0.05%, and Sb: 0.001 to 0.05%; with the balance being Fe and unavoidable impurities, wherein the steel sheet has a steel microstructure in which, in a region extending from 300 to 400 μm from a surface layer of the steel sheet in a thickness direction of the steel sheet, the total area fraction of martensite and bainite containing carbides is 60 to 100%, and the average grain size of prior austenite is 15 μm or less, and in which, in the region extending from 300 to 400 μm from the surface layer of the steel sheet in the thickness direction of the steel sheet, the ratio of the height of a peak of P in an Auger electron spectrum at a position 5 nm or more from a prior-austenite grain boundary to the height of a peak of P in an Auger electron spectrum at the prior-austenite grain boundary is 0.20 or more, and wherein the steel sheet has a hot-dip galvanized layer on a surface thereof, and wherein the average grain size of prior austenite, the tensile strength and the ratio of the height of a peak of P in an Auger electron spectrum are measured as defined in the description. C:0.08 to 0.35%, Si: 0.01 to 3.0%, Mn: 2.0 to 4.0%, P: 0.010% or less, excluding 0, S: 0.002% or less, excluding 0, Al: 0.01 to 1.50%, and B: 0.0005 to 0.010% and further comprising one or more selected from Mo: 0.03 to 2.0% and Ti: 0.010 to 0.10%, and optionally one or more selected from Nb: 0.005 to 0.20%, V:0.005 to 2.0%, Cr: 0.005 to 2.0%, Ni: 0.005 to 2.0%, Cu: 0.005 to 2.0%, Ca: 0.0002 to 0.0050%, REMs: 0.0002 to 0.0050%, Sn: 0.001 to 0.05%, and Sb: 0.001 to 0.05%; with the balance being Fe and unavoidable impurities, wherein the steel sheet has a steel microstructure in which, in a region extending from 300 to 400 μm from a surface layer of the steel sheet in a thickness direction of the steel sheet, the total area fraction of martensite and bainite containing carbides is 60 to 100%, and the average grain size of prior austenite is 15 μm or less, and in which, in the region extending from 300 to 400 μm from the surface layer of the steel sheet in the thickness direction of the steel sheet, the ratio of the height of a peak of P in an Auger electron spectrum at a position 5 nm or more from a prior-austenite grain boundary to the height of a peak of P in an Auger electron spectrum at the prior-austenite grain boundary is 0.20 or more, and wherein the steel sheet has a hot-dip galvanized layer on a surface thereof, and wherein the average grain size of prior austenite, the tensile strength and the ratio of the height of a peak of P in an Auger electron spectrum are measured as defined in the description.