The hypothalamic-pituitary-gonadal (HPG) axis is a key biological system required for reproduction and associated sexual behaviors to occur. In the avian model, the rock dove (Columba livia), we characterized the transcript community of each tissue of the HPG axis in both sexes. We report greater sex-biased differential expression in the pituitary (233 genes out of 15,102 genes) as compared to the hypothalamus (1 gene out of 15,102 genes), with multiple genes overexpressed in the male pituitary gland being related to locomotion, and multiple genes over-expressed in the female pituitary gland being related to reproduction, growth, and development. These genes may be associated with facilitating the different roles the HPG system plays in sex-specific reproductive behavior, including life-history strategies characterized by short-term payoffs in males (i.e. locomotion) and longer-term payoffs in females (i.e. development and reproduction). In addition, we report novel patterns of sex-biased expression in genes involved in reproduction-associated processes, including gonadotropin-releasing hormone-I, prolactin, progesterone receptor, androgen receptor, and arginine vasopressin-like receptor 1A. We discovered other interesting sex-biased patterns in genes that may play important, though currently unknown, roles in reproductive physiology and behavior, such as Betacellulin (BTC) and Ecto-NOX Disulfide-Thiol Exchanger 1 (ENOX1). In summary, we offer a resource to greatly expand our mechanistic insight into HPG activity. We report tissue-specific and sex-biased expression in genes commonly investigated when studying reproduction, highlighting the need for sex parity in all future studies. In addition, we uncover new targets of investigation in both sexes, which could potentially change our understanding of HPG function.