Time-variant channels degrade the performance of Orthogonal Frequency Division Multiplexing (OFDM) systems because they collapse the orthogonality between the sub-carriers, which necessitates estimating the resulting off-diagonals of the channel matrix in order to properly equalize the received signal. This letter presents a new method of estimating the channel matrix for OFDM systems in rapidly time-variant channels. The method approximates the time variation of the channel over a few successive OFDM symbols making use of Newton polynomial interpolation.