The species epithet watsoni honours zoologist Dr Graeme Watson, formerly of the University of Melbourne, for his lifetime contributions to the study of frog biology.

[2] The species is very similar to Littlejohn's tree frog; the main distinguishing characteristic is the breeding call of the males, with Watson's tree frog uttering fewer pulses in each note (with a mean of 22.8 per second as compared to 27.8) for a call length of 3–12  seconds.

The topography of the northern end of the distribution range is characterised by steep cliffs and valleys, forming a biogeographic barrier which marks the geographic separation between Littlejohn's and Watson's tree frogs.

The most important habitat factor is the presence of pools that contain water long enough for tadpoles to complete metamorphosis.

Threatening factors include habitat loss as well as bushfires, the incidence of which is likely to increase with climate change.