We compute the electroweak (EW) contributions to squark-squark pair production processes at the LHC within the framework of the Minimal Supersymmetric Standard Model (MSSM). Both tree-level EW contributions, of $ \mathcal{O}\left( {{\alpha_s}\alpha + {\alpha^2}} \right) $, and next-to-leading order (NLO) EW corrections, of $ \mathcal{O}\left( {\alpha_s^2\alpha } \right) $, are calculated. Depending on the flavor and chirality of the produced squarks, many interferences between EW-mediated and QCD-mediated diagrams give non-zero contributions at tree-level and NLO. We discuss the computational techniques and present an extensive numerical analysis for inclusive squark-squark production as well as for subsets and single processes. While the tree-level EW contributions to the integrated cross sections can reach the 20% level, the NLO EW corrections typically lower the LO prediction by a few percent.