The dwarf flathead gudgeon (Philypnodon macrostomus) is a species of sleeper goby endemic to eastern Australia.

P. macrostomus was described in 2006 by Douglass Fielding Hoese and Sally Reader; the type specimen was collected in Glenreagh, New South Wales.

It can be distinguished from the flathead gudgeon, which is larger, has a wider gill opening, and has vertical stripes on the sides of the belly.

[4] The dwarf flathead gudgeon is found in estuaries and freshwater rivers from Baffle Creek in central Queensland through New South Wales and eastern Victoria to Wilsons Promontory.

[5] The dwarf flathead gudgeon is commonly found alongside its larger relative,[4] and often near some form of cover such as submerged vegetation or rocks.