Edward Bransfield (1783-1852) from Cork - a master in the navy who visited the South Shetland Islands in 1820 and made a rough survey of the islands. In the same year he discovered Trinity Land, the north western tip of the Antarctic Peninsula. Shortly afterwards he claimed King George and the Clarence Island for Britain.
http://en.wikipedia.org/wiki/Edward_Bransfield
http://www.beyondendurance.ie/history/explorer/6

Edward Sabine (1788 –1883) was a Dublin-born astronomer, scientist, ornithologist and explorer In 1818 he travelled as the expedition's astronomer with his friend, Sir Clark Ross, to find the North-West Passage. He also joined the 1819-20 Arctic expedition of William Parry. http://www.todayinsci.com/S/Sabine_Edward/Sabine_Edward.htm
http://en.wikipedia.org/wiki/Edward_Sabine

Tom Crean (1877 –1938) was born in Annascaul in Co. Kerry. He joined the Royal Navy when he was 15 years old, lying about his age to get in. He was on three of the four major British expeditions to Antarctica. Two of these were expeditions led by Robert Scott; the 1901-1904 National Antarctic Expedition on Discovery and the 1911-1913 expedition on Terra Nova . The third was the Imperial Trans-Antarctic Expedition on Endurance led by Ernest Shackleton.
http://www.teachnet.ie/ffleming/teachnet2006/pages/
http://www.coolantarctica.com/Antarctica%20fact%20file/History/biography/crean_thomas.htm
http://www.tomcrean.com/N_antarctic_hero.htm
http://www.70south.com/information/antarctic-history/explorers/tomcrean

Henry Kellett (1806 – 1975) officer in the Royal Navy, oceanographer, Arctic explorer; born at Clonabody, Tipperary, Ireland. In 1845 he was appointed captain of the survey ship HMS Herald, being reassigned in 1848 to join the search for Sir John Franklin. During this voyage he sailed through the Bering Strait and discovered Herald Island, from where he had distant views of Wrangel Island. In 1852, he commanded HMS Resolute and went to the aid of Robert McClure, whose vessel, Investigator, was trapped in the Arctic.
http://www.biographi.ca/EN/ShowBio.asp?BioId=39194
http://en.wikipedia.org/wiki/Henry_Kellett

Henry Gore-Booth, Sligo: (1843 –1900), was a notable Arctic explorer, adventurer and landowner from Lissadell House, Sligo, Ireland. http://en.wikipedia.org/wiki/Sir_Henry_Gore-Booth,_5th_Baronet

Captain Francis Crozier from Banbridge, County Down. (1796–1848?)  He was a British naval officer who participated in six exploratory expeditions to the Arctic and Antarctic. In 1845 he joined Sir John Franklin on the Northwest Passage Expedition as captain of HMS Terror. Following Franklin's death in June, 1847 he took command of the expedition. He presumably perished in the Arctic region in 1848,
http://website.lineone.net/~polar.publishing/captaincrozier.htm
http://en.wikipedia.org/wiki/Francis_Crozier

Sir Robert McClure (1807 – 1873) born in Wexford was an explorer of the Arctic. He was sent by Beaufort in 1850 through the Pacific and into the Bering Straits to seek the western entrance to the North-West Passage. He discovered the Prince of Wales Straits and the Banks and Victoria islands. He is credited factually as the first man to discover the existence of the North-West Passage. He died a Vice Admiral in 1873.  http://www.collectionscanada.ca/explorers/h24-1840-e.html
http://en.wikipedia.org/wiki/Robert_McClure

Leopold McClintock (1819 – 1907) Born in Dundalk he was an Irish explorer in the British Royal Navy who is known for his discoveries in the Canadian Arctic Archipelago. He joined a series of searches for Sir John Franklin between 1848 and 1859. He mastered traveling by using human hauled sleds, which remained the status quo in Royal Navy Arctic and Antarctic overland travel until the death of Captain Robert Falcon Scott. In 1857 he was given command of the yacht "Fox" which was sponsored by public subscription via Lady Jane Franklin's search for her missing husband. They eventually discovered cairns that gave evidence of what had happened to Franklin and his second in command, Captain Francis Crozier. http://www.northabout.com/nwp/leopold.htm
http://en.wikipedia.org/wiki/Francis_Leopold_McClintock

Ernest Shackleton (1874 –1922) born in Co. Kildare, was an Irish explorer who took part in Scott’s “Discovery” expedition of 1901-02. He led his own Nimrod Expedition in 1907–1909 and established a “furthest south” record reaching within 100 miles of the south pole. He is best remembered today for his Antarctic expedition of 1914–1916 when his ship Endurance was crushed by the ice and he managed to save all his men. He died at South Georgia during his Quest expedition and is buried on that island.
http://www.south-pole.com/p0000097.htm
http://www.solarnavigator.net/history/sir_ernest_shackleton.htm
http://www.bbc.co.uk/history/british/britain_wwone/launch_ani_shackleton.shtml
http://www.spri.cam.ac.uk/library/archives/shackleton/

Athy Heritage Centre and Museum has a Shackleton display : http://athyheritagecentre-museum.ie/shackleton/index.php

Cork man Robert Forde was 35 years of age when he joined Scott’s Terra Nova as Petty Officer on May 30th 1910. Cork man Patrick Keohane was 30 years of age when he was selected to join Scott’s Terra Nova expedition. http://www.south-pole.com/p0000090.htm

Brothers Mortimer and Tim McCarthy from Kinsale were both participants in Antarctic expeditions with Scott and Shakleton. Mortimer joined the crew of Scott’s Terra Nova in 1910. Tim took part in Shackleton’s Endurance expedition and was one of the crew of the James Caird for the voyage from Elephant Island to South Georgia.  http://www.beyondendurance.ie/history/explorer/6

Harry Dunlop, born Belfast, Ireland, 1876. One of the ship’s crew of Shackleton’s expedition ship Nimrod 1907-1909 serving as First Engineer for both voyages south. He served his time with the world-famous engineering firm Harland and Wolff. Dunlop Island 77o14’S. 163o30’E is named after him. http://www.south-pole.com/p0000097.htm