In this paper, we propose a multipath division SC/MMSE turbo equalizer for multicarrier systems with insufficient cyclic prefix (CP). In the proposed scheme, the received paths, which include paths that exceed the length of the CP, are divided into several blocks. Therefore, inter-symbol interference and inter-carrier interference, which are caused by large delayed paths, can be mitigated by making the paths in each block shorter than or equal to the CP length through multipath division. Moreover, path diversity gain can be obtained when paths in each block are combined by the MMSE filter. Therefore, this proposed turbo equalization can realize the reduction of both ISI and ICI with low complexity. In order to evaluate the effectiveness of the proposed scheme, we perform computer simulation. The simulation results show that the proposed scheme can drastically improve PER characteristics.