In the embryo, Abelson tyrosine kinase (Abl) is expressed in the central nervous system (CNS), and is localized to the axons of neuronal cells where it acts downstream of axon guidance receptors such as Frazzled and Roundabout. While the Abl N-terminus is highly conserved between Abl proteins of diverse taxa, the sequence of the Drosophila Abl C-terminal domain (CTD) of ~1100 amino acids is largely unique, with the exception of a conserved F-actin binding domain at the tail end. Here, we demonstrate that the CTD is essential for the recruitment of Abl to axon tracts. Using the Gal4-UAS system and immunohistochemistry, we confirm that removal of the CTD prevents the remaining N-terminal region from localizing to axons, and demonstrate that the CTD alone is sufficient for localization to axons. Within the CTD, we further define a ~350 amino acid region (amino acids 1117-1492, or the “third quarter”) that is sufficient to drive localization of an RFP fusion protein to axons. However, in the context of full-length Abl, removal of the third quarter does not completely prevent axon localization, although stability of the protein is decreased, resulting in overall lower levels of Abl in the axons. Within the third quarter, the two putative EVH1 binding motifs are not required for axonal localization. Surprisingly, adult lethality assays using the expression of Abl transgenes in Abl mutant flies indicate that a second region, not involved in axonal localization (amino acids 639-804), is essential for Abl function, and ubiquitous or neuronal expression of the N-terminus fused to this region partially rescues adult lethality despite the protein’s inability to localize to axons. Bioinformatic analyses suggest that large regions of the C-terminus are disordered, and these may undergo a disorder-to-order transition during protein-protein interactions. This further suggests that the C-terminus primarily facilitates binding of Abl to target proteins. Work is underway to both identify binding targets of the CTD as well as to assess the ability of our Abl transgenes to rescue axon guidance defects in Abl mutant embryos. As a whole, these results identified a region that is sufficient for axonal localization (the third quarter) although in the context of full-length Abl, this region may further co-operate with other regions for localization. Our results also suggest that the C-terminus has additional essential functions besides axonal localization.