Sixty-miler (60-miler) is the colloquial name for the ships that were used in the coastal coal trade of New South Wales, Australia. The sixty-milers delivered coal to Sydney from ports and ocean jetties to the north and south. The name refers to the approximate distance by sea from Newcastle to Sydney; the distance, from the Hunter River mouth at Nobbys Head to the North Head of Sydney Harbour, is 64 nautical miles.

The coastal coal-carrying trade of New South Wales, involved the shipping of coal to Sydney for local consumption or for bunkering steamships. The coal was carried from ports of the northern and southern coal fields of New South Wales to Sydney. It took place in the 19th and 20th centuries. It does not refer to export coal trade that used larger vessels and continues today.

Coal from the northern coalfields was loaded at Hexham on the Hunter River, Carrington (The Dyke and The Basin) and Stockton both near Newcastle, at jetties on Lake Macquarie, and at the ocean jetty at Catherine Hill Bay. In the early years of the trade, coal was loaded at Newcastle itself on the southern bank of the Hunter River, at the river port of Morpeth, and at a wharf at Reid's Mistake at Swansea Heads.

Coal from the southern coal fields, at various times, was loaded at Wollongong Harbour and Port Kembla and at the ocean jetty ports: Bellambi; Coalcliff; Hicks Point at Austinmer; and Sandon Point, Bulli. Port Kembla was originally an ocean jetty port but two breakwaters were added later to provide shelter.

At Sydney, coal wharves were located at the gasworks (Millers Point, Mortlake, Neutral Bay, Waverton and Spring Cove at Manly). Coal was unloaded at the Ball's Head Coal Loader—for steamship coal bunkering and in later years for export—and at the coal depot at Blackwattle Bay. Before the Ball's Head Coal Loader opened in 1920, coal was manually loaded by 'coal lumpers' to steamship bunkers, from sixty-milers standing alongside. Some industrial customers, such as CSR at Pyrmont, had their own facilities to unload coal

Coal was also unloaded on Botany Bay, from time to time, at the Government Pier (or 'Long Pier') at Botany and also for various customers at wharves located on the banks of the Alexandra Canal (also known as Shea's Creek).

Sixty-milers sometimes also carried crushed basalt construction aggregate—or blue metal—from the port at Kiama and the ocean jetty at Bass Point (Shellharbour) on the South Coast of New South Wales. The blue metal was unloaded at Blackwattle Bay in Sydney Harbour. There was also a similar type of small bulk cargo ships, usually dedicated to carrying construction aggregate, known as the Stone Fleet. Some 'Stone Fleet' ships carried coal from time to time.

Although the earliest sixty-milers were sailing vessels, the term was most typically applied to the small coal-fired steamers with reciprocating engines that were used during the late 19th and 20th Centuries. In the last years of the coastal coal trade, some sixty-milers were diesel-powered motor vessels.