Alpine climbing (German: Alpinklettern) is a type of mountaineering that uses any of a broad range of advanced climbing techniques, including rock climbing, ice climbing, and/or mixed climbing, to summit typically large rock, ice, or snow-covered climbing routes (e.g., multi-pitch or big wall climbs) in mountainous environments. Alpine climbing began in the European Alps, but is now performed in any remote mountainous area, including in the Himalayas and Patagonia. To climb alpine style is to do so in small lightly-equipped teams who carry all their equipment (e.g., no porters are used) and do all of the climbing themselves (e.g., no sherpas or reserve teams).

Alpinists face many additional risks beyond the risks of falling that is associated with the activity of rock and ice climbing. These risks include major rockfalls (common with large sheer rock faces in alpine environments), of avalanches (especially in couloirs), of falling seracs and of falling into crevasses, of violent storms on exposed mountain faces, of altitude effects (dehydration, edema, frostbite), of complex navigation and route finding, of long dangerous abseils, and of the difficulty of rescue or retreat due to the remoteness of the setting. Long routes may require alpinists to move simultaneously to maintain speed (e.g., in simul climbing or as rope teams), which carries its own risks.

The first "golden age" of modern alpine-climbing saw the first free ascents – in summer, in winter, and as solo – of the great north faces of the Alps by pioneers such as Walter Bonatti, Riccardo Cassin and Gaston Rebuffat. Today's subsequent era focuses on the ascents and enchainments of the ice and snow-covered faces and ridges of major Himalayan peaks (e.g., the eight-thousanders, Latok, and The Ogre in Pakistan) and Patagonian peaks (e.g., Cerro Torre Group, Fitz Roy Group in South America) in "alpine style" by pioneers such as Hermann Buhl, Reinhold Messner and Doug Scott, and latterly by alpinists such as Ueli Steck, Mick Fowler, Paul Ramsden, and Marko Prezelj. The annual Piolets d'Or – the "Oscars of mountaineering" – are awarded for the year's best achievements in alpine climbing.

Alpine climbing involves small unsupported teams tackling large multi-pitch (or big wall) climbing routes that can involve various combinations of rock climbing, ice climbing, and mixed climbing, in alpine-type mountain environments. Alpine routes are often long and require a full day of climbing, or even several days. Because of the length of the routes, and the danger of alpine environments (e.g. rockfall, avalanche, altitude, weather, etc.), alpine climbers (or "alpinists") typically try routes that are well within their technical rock, ice, and mixed climbing abilities.

While parts of an alpine route will involve a lead climber tackling difficult rock, ice, or mixed sections while being belayed by a stationary second climber below, parts will involve both climbers moving simultaneously together as a rope team, particularly on large snow slopes or easier rock sections. Simultaneous climbing (or simul climbing) is riskier but is necessary to ensure that the climbers can move quickly through what is often a very dangerous and exposed environment (e.g. rockfall on open ice fields), and complete the long alpine climbing routes in a reasonable timeframe.

Alpine climbing can involve aid climbing, particularly if high up on a route, aid is needed to make progress and avoid a dangerous retreat. It can also involve multiple and complex abseils, either on the descent or in a retreat from a route. Classic alpine climbing routes often take at least a full day of climbing which necessitates the early "alpine start" (and helps to avoid the afternoon rockfalls), and may need a bivouac. It often involves traveling on glaciers and bergschrunds to get to and from the route (and in the dark for "alpine starts").

Due to the greater complexity and risks of alpine climbing, alpinists need to be much more familiar with and confident in each team member's abilities and skill level. Alpine climbing involves exercising judgment and decision-making to adapt to the constantly changing alpine weather and route conditions (e.g. changing snow and ice levels), and where good initial progress can quickly turn into a fight for the team's very survival (e.g. as chronicled during many famous alpine climbs of north-faces, such as in The White Spider that recounts the 1936 Eiger climbing disaster).

The derived term "alpine style" alludes to the fashion of alpine climbing to be in small fast-moving teams – or even as solo climbing – all of whom carry their own equipment (e.g. no porters), and do all of the climbing (e.g. no Sherpas or reserve teams laying down fixed ropes). Alpine-style is the opposite of expedition style (which is sometimes also pejoratively called "siege style" climbing), and is often considered a "purer" form of climbing and mountaineering.