•
Meherban Karim (1979–2008) Pakistan, Gasherbrum II, Nanga Parbat, K2 without supplementary oxygen •
Ashish Mane (born 1990) India, Everest (2012), Lhotse (2013), Makalu (2014), Manaslu (2017) •
Tim Macartney-Snape (born 1956) Australia, Everest (1984), first to climb Everest from sea level (1990) •
Tomasz Mackiewicz (1975–2018) Poland, died on winter alpine-style ascent of
Nanga Parbat •
Dave MacLeod (born 1978)
Scotland, made the first free ascent of the world's first E11 traditional climbing route •
M. Magendran (born 1963) Malaysia, Everest (1997), first Malaysian/Tamil to reach the summit •
Nasuh Mahruki (born 1968) Turkey, Snow Leopard, first Turkish and Muslim climber of Everest •
Janusz Majer (born September 25, 1946) Poland •
Maki Yūkō (1894–1989) Japan, first ascents of Mittellegigrat (Eiger northeast ridge),
Mount Alberta; first winter ascent of
Mount Yari; led
Manaslu first ascent •
Tashi and Nungshi Malik (born 1991) India, many world first female twins records •
George Mallory (1886–1924) UK, initial
1921 British Reconnaissance Expedition and the
1922 and
1924 British Mount Everest expeditions, died on Everest at 8,150+ metres •
Sergio Martini (born 1949) Italy, seventh ascent of all eight-thousanders (1983–2000) •
Marie Marvingt (1875–1963) France, first woman to climb most major peaks in the French and Swiss Alps (1903–7) •
William Mathews (1828–1901) UK, founder of
Alpine Club, first ascent
Monte Viso,
Grande Casse •
Chantal Mauduit (1964–1998) France, six 8,000m summits without supplementary oxygen, died on
Dhaulagiri •
John Oakley Maund (died 1902) UK, first ascents in Mont Blanc massif •
Eylem Elif Maviş (born 1973) Turkey, first Turkish female ascent of Everest (2006) •
Pierre Mazeaud (born 1929) France,
Walter Bonatti's climbing partner, first French ascent of Everest (1978) •
Daniel Mazur (born 1960) US, numerous ascents in the Himalayas and America •
Steve McClure (born 1970) UK, first Briton to climb 9a twice •
Duncan McDuffie (1877–1951) US, summits in the
Sierra Nevada •
Richard "Dick" McGowan (1933–2007) US, first US successful ascent of Everest, International Himalayan Expedition (1955) •
Ammon McNeely (born 1970) US, noteworthy first one-day ascents and speed records on El Capitan,
Yosemite and Zion big walls •
Alex Megos (born 1993) first climber to on-sight 5.14d/9a route •
Willy Merkl (1900–1934) Germany, led two expeditions to
Nanga Parbat (1932, 1934), died on the mountain •
Alain Mesili (born 1949) France, disputed ascent on
Fitz Roy (1970) with Ricardo Arzela, pioneered routes in Bolivia •
Günther Messner (1946–1970) Italy, died on Nanga Parbat •
Reinhold Messner (born 1944) Italy, first to climb all eight-thousanders (1970–1986) and without supplementary oxygen, first ascent without supplementary oxygen of Everest with
Peter Habeler (1978) first solo Everest (1980) •
Tracee Metcalfe US, only living American woman to have climbed 13 of the 14 eight-thousanders •
Enid Michael (1883–1966) US, known for
ropeless climbing in Yosemite in the early 1900s •
John Middendorf (born 1959) US, big-wall rock climber, first ascent East Wall
Great Trango Tower (1992) •
Thomas Middlemore (1842–1923) UK, first ascents in Mont Blanc and Bernina massifs, and Bernese Alps •
Ellen Miller (born 1959) US, first American woman to summit Nuptse and Everest from both sides •
Gwen Moffat (born 1924) UK, author of
Space Below My Feet (1961) •
Jerry Moffatt (born 1963) UK, sport climber and boulderer •
Silvio Mondinelli (born 1968) Italy, 13th to climb all eight-thousanders (sixth without supplementary oxygen) •
Park Moo-taek (1969–2004) Korea, former Guinness World Record holder for fastest time to climb the world's three tallest mountains •
Ben Moon (born 1966) UK, sport climber, and boulderer, world's first with
Hubble •
A. W. Moore (1841–1887) UK, first ascent
Fiescherhorn,
Barre des Écrins,
Piz Roseg,
Ober Gabelhorn •
Tyrhee Moore US, member of the first all-African-American team to climb Denali •
Martin Moran (1955-2019) UK, mountain guide and author •
Fritz Moravec (1922–1997) Austria, first ascent
Gasherbrum II (1956) •
Piotr Morawski (1976–2009) Poland, many 8000m summits, died on Dhaulagiri/Manasu expedition •
Nea Morin (1905–1986) UK, rock climber and mountain climber •
Simone Moro (born 1967) Italy, first winter ascents of
Shishapangma,
Makalu,
Gasherbrum II, and
Nanga Parbat •
Don Morrison (1929–1977) UK, pioneer of
Alpine Style, first ascents in Canada, England, and Himalayas •
Patrick Morrow (born 1952) Canada, first to complete both Bass and Messner Seven Summits lists (1986) •
Tomáš Mrázek (born 1982) Czechoslovakia, rock climber, World Champion 2003, 2005, winner of World Cup 2004 •
John Muir (1838–1914) Scottish-born US conservationist and mountaineer, summits in
California and
Alaska •
Norrie Muir (1948–2019) Scotland, prolific winter first ascentionist in Scotland •
Albert F. Mummery (1855–1895) UK, Alpine and Himalayan pioneer, killed on
Nanga Parbat •
Don Munday (1890–1950) Canada, mountaineer and explorer, husband of
Phyllis Munday, explored region around
Mount Waddington •
Phyllis Munday (1894–1990) Canada, mountaineer and explorer, explored region around
Mount Waddington •
Malli Mastan Babu (1974–2015) India, mountaineer and explorer, world record in completing seven summits in 172 days == N ==