Abstract: It is an object to provide a regenerated denitration catalyst whose denitration performance is restored compared with a denitration catalyst before use, utilizing a spent denitration catalyst, and a method for manufacturing the same. In a regenerated denitration catalyst according to the present disclosure, a spent denitration catalyst including a first titanium oxide as a main component, and a second titanium oxide are mixed. The spent denitration catalyst is already used in a denitration reaction in which nitrogen oxides in a gas are decomposed into nitrogen and water using a reducing agent. The second titanium oxide has a larger specific surface area per unit weight than the first titanium oxide. A content of the second titanium oxide based on a total weight of the first titanium oxide and the second titanium oxide is preferably 10% by weight or more and 90% by weight or less.