While sex chromosomes often evolve in species with separate sexes through similar processes, there are also many differences in their evolutionary dynamics. In palms, a clade with 8-10 independent evolutionary origins of dioecy, sex chromosomes have hitherto been well characterized only in the date palm genusPhoenix. Using genome-wide target capture sequencing, we found that the same region independently became sex-linked both inPhoenixand in the rather distantly related speciesKerriodoxa elegans. Investigating the gene content of this region revealed it contains many genes involved in flower sex differentiation which might be the reason for this case of convergent evolution. This region, which could function as a “genetic toolbox” for the production of unisexual flowers or individuals, may have an ancestral functional importance in palm genomes.