HMAS Melbourne commissioned at Birkenhead, England, on 18 January 1913 under the command of Captain Mortimer L’Estrange Silver, RN. The ship completed her delivery voyage from England when she arrived at Fremantle on 10 March 1913.
Following the outbreak of war in August 1914, Melbourne spent a brief period in Pacific waters as a unit of the Australian Squadron to prevent attacks by the German Pacific Squadron under Admiral Graf von Spee. She took part in the seizure of the German Pacific possessions, and on 9 September 1914 landed a naval party on Nauru Island to carry out the destruction of the wireless station. Her return to Sydney on 20 September 1914 ended this phase of operations. The cruiser covered 11,170 miles on Pacific patrols.
On the night of 21/22 January 1922 HMAS Melbourne was involved in the dramatic rescue of 18 people from the sinking US registered schooner Helen B Sterling. The Helen B Sterling had departed Newcastle in early January bound for San Francisco with a cargo of coal. The schooner encountered a storm north of New Zealand and began to sink. Fortunately the Helen B Sterling had a wireless on board and sent out a distress call which was received by Melbourne, then on a deployment to New Zealand waters.