Disclosed is a channel estimation method and apparatus in an OFDM system. The method includes performing channel estimation at a pilot position of a received symbol, thereby calculating a first channel estimate, performing diagonal interpolation between the first channel estimate and a channel estimate for another pilot position that is different from the first pilot position, thereby calculating a second channel estimate for a data position, performing time interpolation between the second channel estimate and a channel estimate for another pilot position that is identical to the second pilot position, thereby calculating a third channel estimate for another data position, and performing frequency interpolation by using the channel estimates for the pilot positions and the second and third channel estimates, thereby calculating channel estimates for remaining data positions.