SignificanceThe split-Gal4 system allowsDrosophilaresearchers to drive transgene expression with extraordinary cell type specificity. However, the existing split-Gal4 system cannot be controlled temporally, and therefore cannot be applied to many important areas of research. Here, we present a split-Gal4 system based on a self-excising split-intein, which is controllable by Gal80, as well as a related drug-inducible split GeneSwitch system. This approach can both leverage and inform single-cell RNAseq datasets, and we introduce an algorithm to identify pairs of genes that precisely and narrowly mark a desired cell cluster. Our split-intein Gal4 system will be of value to theDrosophilaresearch community, and allow for the creation of highly specific genetic drivers that are also inducible/repressible.