As with most of the genus "Sillago", the eastern school whiting has a slightly compressed, elongate body tapering toward the terminal mouth, with the body covered in small ctenoid scales extending to the cheek and head. The most reliable features for distinguishing the species are the number of fins spines and rays and the shape of the swim bladder. The first dorsal fin has 11 spines and the second dorsal fin has 1 leading spine with 16 to 18 soft rays posterior. The anal fin is similar to the second dorsal fin, but has 2 spines with 18 to 20 soft rays posterior to the spines. Other distinguishing features include 69 to 76 lateral line scales and a total of 32 to 34 vertebrae. The species has a known maximum length of 33 cm.