A hydrodesulfurization catalyst supports one or more metals selected from elements in Group 6 of the Periodic table, one or more metals selected from elements in Group 9 or Group 10 of the same, phosphorus, and an organic acid on a composite oxide support having a specific content of both alumina and HY zeolite having a specific crystallite size. The catalyst includes 10% to 40% by mass of the Group 6 metal, 1% to 15% by mass of the Group 9 or Group 10 metal, and 1.5% to 8% by mass of phosphorus in terms of an oxide based on the catalyst. The catalyst includes 0.8% to 7% by mass of carbon derived from an organic acid and for 1 mole of the Group 9 or Group 10 element metal in terms of an element based on the catalyst, and includes 0.2 to 1.2 moles of the organic acid.