Pistols, muskets, rifles, machine guns, swords, knives, bayonets, artillery pieces and armour; are some of the broad range of weapons and associated items that comprise the Arms Collection. Mostly from the eighteenth to the twentieth centuries, the collection is useful for understanding the technical development of firearms and munitions, military, social and political history, and the aesthetics of decoration and craftsmanship during his time. As of 2013 there were 3,818 items in the collection.
The most significant collection of its type held in Australia, especially in terms of non-military firearms, it is also one of Museums Victoria's oldest and most extensive collections. It commenced in 1860 with the acquisition 287 weapons from the Indian Mutiny of 1857-1859. From 1870 when defence became the responsibility of the Victorian colonial government items were also acquired to enable local gunsmiths and mechanics to study the principles and techniques of firearms manufacture. In the twentieth century the collection developed in three key ways: donations and transfers from military sources; transfers from Victoria Police and other police forces; and the acquisition of local private collections.