Rock Flat Creek is a watercourse[1] that is part of the Murrumbidgee catchment within the Murray–Darling basin.

Rock Flat Creek (technically a river[1]) rises below One Tree Hill, on the lower slopes of the Snowy Mountains, part of the Great Dividing Range.

The creek flows generally north by west before reaching its confluence its tributary, Cooma Creek, and then flows into Numeralla River (itself a tributary of the Murrumbidgee River), north of the town of Cooma.

[2] The Monaro Highway crosses the creek near the locality of Milton Park.

[2] Near the Monaro Highway crossing,[3] there is a mineral spring that comes to the surface, on the bank of Rock Flat Creek, about 16 km south-east of Cooma.