A method and apparatus for detecting a format of closed caption data contained in a broadcast signal automatically and displaying the caption data are provided. The method includes: (a) receiving information including closed caption data extracted from the broadcast signal, (b) detecting information on the format of the closed caption data from the received information including the closed caption data and determining the format of the closed caption data, and (c) decoding the closed caption data according to the determined format of the closed caption data and displaying the caption data to a user.