Non-mammalian models are powerful systems for enhancing our understanding of lysosomal function and lysosomal storage diseases. The social amoeba Dictyostelium discoideum is an excellent model organism for studying lysosomal function, as its genome encodes many proteins associated with lysosomal disease. Methods for gene knockout are straightforward in D. discoideum and include restriction enzyme-mediated integration (REMI) mutagenesis, homologous recombination via the Cre-loxP system, and CRISPR/Cas9-mediated gene editing, which collectively allow researchers to study protein function (e.g., lysosomal enzymes) in a genetically tractable biomedical model system. Additionally, activity assays for conserved lysosomal enzymes are well-established in D. discoideum. In this chapter, we outline methods for studying the intracellular localization and secretion of conserved lysosomal proteins in D. discoideum.