Ernest Edward Mills Joyce AM (c. 1875 – 2 May 1940) was a Royal Naval seaman and explorer who participated in four Antarctic expeditions during the Heroic Age of Antarctic Exploration, in the early 20th century. He served under both Robert Falcon Scott and Ernest Shackleton. As a member of the Ross Sea party in Shackleton's Imperial Trans-Antarctic Expedition, Joyce earned an Albert Medal for his actions in bringing the stricken party to safety, after a traumatic journey on the Great Ice Barrier. He was awarded the Polar Medal with four bars, one of only two men to be so honoured, the other being his contemporary, Frank Wild.

Joyce came from a humble seafaring background and began his naval career as a boy seaman in 1891. His Antarctic experiences began 10 years later, when he joined Scott's Discovery Expedition as an Able Seaman. In 1907 Shackleton recruited Joyce to take charge of dogs and sledges on the Nimrod Expedition. Subsequently, Joyce was engaged in a similar capacity for Douglas Mawson's Australasian Antarctic Expedition in 1911, but left the expedition before it departed for the Antarctic. In 1914 Shackleton recruited Joyce for the Ross Sea party; despite his heroics this expedition marked the end of Joyce's association with the Antarctic, and of his exploring career, although he made repeated attempts to join other expeditions.

Throughout his career Joyce was known as an abrasive personality who attracted adverse as well as positive comments. His effectiveness in the field was widely acknowledged by many of his colleagues, but other aspects of his character were less appreciated – his capacity for bearing grudges, his boastfulness and his distortions of the truth. Joyce's diaries, and the book he wrote based on them, have been condemned as self-serving and the work of a fabulist. He made no significant material gains from his expeditions, living out his post-Antarctic life in humble circumstances before dying in 1940.

Joyce's Royal Navy service record show his place and date of birth at Feltham (Felpham), Sussex, 22 December 1875. Kelly Tyler-Lewis, in her account of the Ross Sea party, quotes a newspaper report giving Joyce's age as 64 in 1939, indicating birth year as 1875 – although she also gives his age as 29 in 1901, suggesting an earlier birth year. Joyce's father and grandfather had both been sailors, his father probably within the coastguard service. After the father's early death his widow, with three children to support on her limited earnings as a seamstress, sent the young Ernest to the Lower School of Royal Hospital School at Greenwich. Here, in austere surroundings, he received a vocational education that would prepare him for a lower-deck career in the Royal Navy. After leaving the school in 1891, he joined the navy as a boy seaman, progressing over the next ten years to Ordinary Seaman and then Able Seaman. Joyce had blue eyes and a fair complexion, with a tattoo on his left forearm and a scar on his right cheek. He was not a tall man, only 5' 7" in height.

In 1901 he was serving on Gibraltar in Cape Town where, in September, Scott's expedition ship Discovery stopped on the way to the Antarctic. Scott was short-handed, and requested volunteers; from a response of several hundreds, Joyce was one of four seamen chosen to join Discovery. He sailed south with her on 14 October 1901.

The Discovery Expedition was Joyce's Antarctic baptism, although for the next three years he kept a relatively low profile; Scott scarcely mentions him in The Voyage of the Discovery, and Edward Wilson's diaries not at all. It seems that he took readily to Antarctic life, gaining experience in sledging and dog-driving techniques and other aspects of Antarctic exploration. He did not figure in the main journeys of the expedition, although towards the end he joined Arthur Pilbeam and Frank Wild in an attempt to climb Mount Erebus, ascending to some 3,000 feet (910 m). Joyce was at times badly affected by frostbite; on one occasion two officers, Michael Barne and George Mulock, held Joyce's frostbitten foot against the pits of their stomachs and kneaded the ankle for several hours to save it from amputation. However, such experiences left Joyce undaunted; the polar historian Beau Riffenburgh writes that Joyce was repeatedly drawn to the Antarctic by "a curious combination of affection and antipathy" that "impelled [him] to return again and again".

During the expedition Joyce encountered several men who would feature prominently in Antarctic polar history during the following years, including Scott, Wilson, Frank Wild, Tom Crean, William Lashly, Edgar Evans and, most significantly, Ernest Shackleton. Joyce made several sledging trips with Shackleton and created an impression of competence and reliability. He also impressed Scott as "sober, honest, loyal and intelligent", and expedition organiser Sir Clements Markham later described him as "an honest and trustworthy man". His reward, at the conclusion of the expedition, was promotion to Petty Officer 1st Class on Scott's recommendation. However, he had been bitten by the bug of Antarctic exploration, and ordinary naval duty no longer appealed. He left the navy in 1905 but found shore life unsatisfying and re-enlisted in 1906. When the chance came a year later to join Shackleton's Nimrod Expedition, he took it immediately.

When Shackleton was selecting the crew for his Antarctic expedition in Nimrod, Joyce was one of his earliest recruits. Most accounts tell the story that Shackleton saw Joyce on a bus that was passing his expedition offices, sent someone out to fetch him, and recruited him on the spot. To join the expedition, Joyce bought his release from the Navy; in later years he would claim that Shackleton had failed to recompense him for this, despite a promise to do so, one of several disputes over money and recognition which would strain his relations with Shackleton. Joyce, Shackleton and Frank Wild were the only members of the expedition with previous Antarctic experience, and on the basis of his Discovery exploits, Joyce was put in charge of the new expedition's general stores, sledges and dogs. Before departure in August 1907, he and Wild took a crash course in printing at Sir Joseph Causton's printing firm in Hampshire, as Shackleton intended to publish a book or magazine while in the Antarctic.