This volume contains the papers presented at the Second Workshop on Second-Order Quantifier Elimination and Related Topics (SOQE 2021) held on November 4, 2021, due to the pandemic situation as an online event, associated with the 18th International Conference on Principles of Knowledge Representation and Reasoning (KR 2021). It continues the SOQE Workshop Series, which was initiated with SOQE 2017 in Dresden.