Provided is an apparatus and method for eliminating an outband interference signal. An apparatus for eliminating an interference signal includes a first mixer, a filter unit, a second mixer, and an operation unit. The first mixer downconverts a received signal containing an outband interference signal. The filter unit extracts the downconverted outband interference signal from the downconverted received signal. The second mixer upconverts the downconverted outband interference signal to restore the outband interference signal to the original frequency band. The operation unit subtracts and eliminates the restored outband interference signal from the received signal.