Ellen Brook is an ephemeral stream which runs from south of Gingin to the Swan River in Western Australia.

The headwaters of Ellen Brook start south of Gingin, in the Wheatbelt region.

From there, Ellen Brook travels south, generally parallel and to the east of Brand Highway, through agricultural land.

From there, it heads south, between Great Northern Highway and Muchea South Road, passing to the west of RAAF Base Pearce in Bullsbrook, before reaching Upper Swan, where it passes under Muchea South Road, past residential areas in The Vines and Belhus, before joining the Swan River in the Swan Valley.

Tributaries to the west of Ellen Brook are sourced by groundwater flowing from the Gnangara Mound.