A method for dynamic optimization of thread assignments for application workloads in an simultaneous multi-threading (SMT) computing environment includes monitoring and periodically recording an operational status of different processor cores each supporting a number of threads of the thread pool of the SMT computing environment and also operational characteristics of different workloads of a computing application executing in the SMT computing environment. The method further can include identifying by way of the recorded operational characteristics a particular one of the workloads demonstrating a threshold level of activity. Finally, the method can include matching a recorded operational characteristic of the particular one of the workloads to a recorded status of a processor core best able amongst the different processor cores to host execution in one or more threads of the particular one of the workloads and directing the matched processor core to host execution of the particular one of the workloads.