In a radio broadcast receiving apparatus and a broadcast frequency detection method, a frequency fm at which a reception strength (an S meter value) that is equal to or greater than a threshold value Th0 and is greater than reception strengths at frequencies (fm−1) and (fm+1) adjacent to the frequency fm by one step by X or more, is detected as a broadcast reception frequency that is a frequency at which a receivable broadcast is performed. The value of X is set so that it increases with the increase in the reception strength (S meter value) at the frequency fm. As a result, a frequency at which a broadcast is performed can be more accurately detected.