The M4 Motorway is a 55-kilometre (34 mi) series of partially-tolled dual carriageway motorways in Sydney, New South Wales designated as route M4. The M4 designation is part of the wider A4 and M4 route designation, the M4 runs parallel and/or below ground to Great Western Highway, Parramatta Road and City West Link, which are part of route A44.

The A4, A44 and M4 are a collection of arterial routes in Sydney, New South Wales that connect the Inner West of Sydney with the outer western suburbs.