Provided herein are PD-L1 binding molecules comprising or conjugated to a toxin, e.g. a Shiga toxin A Subunit derived polypeptide. In some embodiments, the PD-L1 binding molecules are cytotoxic. In some embodiments, the PD-L1 binding molecules are capable of delivering a CD8+ T-cell epitope to an MHC class molecule inside a PD-L1 positive cell. The PD-L1 binding molecules described herein have uses for selectively killing specific cells (e.g., PD-L1 positive tumor cells and/or immune cells); for selectively delivering cargos to specific cells (e.g., PD-L1 positive tumor cells or immune cells), and as therapeutic and/or diagnostic molecules for treating and diagnosing a variety of conditions, including cancers and tumors involving PD-L1 expressing cells (e.g., PD-L1 positive tumor cells or immune cells).