Antimonide-based compound semiconductors are promising candidates for high-frequency, low-power electronic devices as well as a variety of optoelectronic devices. To assist with the design of shallow or thermally stable contacts, we have performed thermodynamic calculations to estimate ternary phase equilibria in many of the transition metal-Ga-Sb systems. We have used the results of our calculations and a limited number of experiments to identify candidates for nonreactive elemental contacts to GaSb. Both W and Re are clearly in thermodynamic equilibrium with GaSb under the conditions considered in our study. Metal gallides and antimonides that are candidates for thermally stable contacts to GaSb are also highlighted.