An important problem for multicarrier systems is frequency offset between a transmitter and receiver, which can substantially deteriorate system performance. In this paper, we propose a frequency-domain fractionally-spaced minimum mean square error (FDFS-MMSE) multiuser detector for multicarrier code-division multiple-access (MC-CDMA) systems. Numerical results show that with frequency-domain oversampling by a factor of two, the proposed FDFS-MMSE receiver can combat frequency offset efficiently, in addition to its near-far resistance and MAI elimination capability