To date there has been little work done on multilevel codes for the space-time environment. In this paper we develop multi-dimensional space-time multilevel codes (ST-MLCs), which partition the 2Nt-dimensional signalling space that spans all Nt transmit antennas. The partitioning is designed to reduce the complexity of detection/ decoding. We also develop a spacetime multistage decoder for the proposed ST-MLC. It allows the detection/ decoding complexity to be significantly reduced compared to a single level approach.