Bacchus Marsh is an urban centre and suburban locality in Victoria, Australia located approximately 50 kilometres north west of the state capital Melbourne and 14 kilometres west of Melton at a near equidistance to the major cities of Melbourne, Ballarat and Geelong. The population of the Bacchus Marsh urban area was 22,223 at June 2018. Bacchus Marsh is the largest urban area in the local government area of Shire of Moorabool.
Traditionally a market garden area producing a large amount of the region's fruits and vegetables, in recent decades it has transformed into the main commuter town on the Melbourne-Ballarat corridor.
It was named after the colonial settler Captain William Henry Bacchus, who saw the great value of this locality as it was situated on two rivers — the Lerderderg and Werribee.