The Aosta Valley (French: Vallée d'Aoste [vale dɔst]; Italian: Valle d'Aosta [ˈvalle daˈɔsta]; Arpitan: Val d'Aoûta) is a mountainous autonomous region in northwestern Italy. It is bordered by Auvergne-Rhône-Alpes, France, to the west; by Valais, Switzerland, to the north; and by Piedmont, Italy, to the south and east. The regional capital is Aosta.

Covering an area of 3,263 km (1,260 sq mi) and with a population of about 128,000, it is the smallest, least populous, and least densely populated region of Italy. The province of Aosta having been dissolved in 1945, the Aosta Valley region was the first region of Italy to abolish provincial subdivisions, followed by Friuli-Venezia Giulia in 2017 (where they were reestablished later). Provincial administrative functions are provided by the regional government. The region is divided into 74 comuni (French: communes).

The official languages are Italian and French; Valdôtain, a dialect of Franco-Provençal, is also officially recognized. Italian is spoken as a mother tongue by 77.29% of the population, Valdôtain by 17.91%, and French by 1.25%. In 2009, reportedly 50.53% of the population could speak all three languages.

The Aosta Valley is an Alpine valley which, with its tributary valleys, includes the Italian slopes of Mont Blanc, Monte Rosa, Gran Paradiso and the Matterhorn; its highest peak is Mont Blanc (4,810 m or 15,780 ft). This makes it the highest region in Italy, according to the list of Italian regions by highest point.

The valleys, usually above 1,600 m (5,200 ft), annually have a cold continental climate (Dfc). In this climate, the snow season is very long, as long as 8 or 9 months at the highest points. During the summer, mist occurs almost every day. These areas are the wettest in the western Alps. Temperatures in January are low, between −7 and −3 °C (19 and 27 °F), and in July are between 20 and 35 °C (68 and 95 °F).

Areas between 2,000 and 3,500 m (6,600 and 11,500 ft) usually have a tundra climate (ET), where every month has an average temperature below 10 °C (50 °F). This climate may be either a kind of more severe cold oceanic climate, with a low summer average but mild winters, sometimes above −3 °C (27 °F), especially near lakes, or a more severe cold continental climate, with a very low winter average. Temperature averages in Plateau Rosa, at 3,400 m (11,200 ft) high, are −11.6 °C (11.1 °F) in January and 1.4 °C (34.5 °F) in July. It is the coldest place in Italy where the climate is verifiable.

In the past, above 3,500 m (11,500 ft), all months had an average temperature below freezing, with a perpetual frost climate (EF). In recent years, however, there has been a rise in temperatures. See, as an example, the data for Plateau Rosa.

• 
  Mont Blanc
• 
  Blue Lake and the Matterhorn
• 
  Mount Castor

Early inhabitants of the Aosta Valley were Celts and Ligures, whose language heritage remains in some local placenames. Rome conquered the region from the local Salassi around 25 BC and founded Augusta Prætoria Salassorum (modern-day Aosta) to secure the strategic mountain passes, and they went on to build bridges and roads through the mountains. Thus, the name Valle d'Aosta literally means "Valley of Augustus".

In 1031–1032, Humbert I of Savoy, the founder of the House of Savoy, received the title Count of Aosta from Emperor Conrad II of the Franconian line and built himself a commanding fortification at Bard. Saint Anselm of Canterbury was born in Aosta in 1033 or 1034. The region was divided among strongly fortified castles, and in 1191, Thomas I of Savoy found it necessary to grant to the communes a Charte des franchises ("Charter of Liberties") which preserved autonomy—rights that were fiercely defended until 1770, when they were revoked to tie Aosta more closely to Piedmont, but which were again demanded during post-Napoleonic times. In the mid-13th century, Emperor Frederick II made the County of Aosta a duchy (see Duke of Aosta), and its arms charged with a lion rampant were carried in the Savoy arms until the reunification of Italy in 1870.

The region remained part of Savoy lands, with the exceptions of French occupations from 1539 to 1563, later in 1691, and then between 1704 and 1706. It was also ruled by the First French Empire between 1800 and 1814. During French rule, it was part of Aoste arrondissement in Doire department. As part of the Kingdom of Sardinia, it joined the new Kingdom of Italy in 1861.

French forces briefly controlled the area at the end of World War II, but withdrew under British and American pressure. The region gained special autonomous status after the end of World War II; the province of Aosta ceased to exist in 1945.

For decades, the valley has been dominated by autonomist regional parties such as the Valdostan Union, which represents the interests of the French-speaking population. The latest regional election was held in September 2020. On 2 March 2023, Renzo Testolin was elected regional president, supported by a coalition of autonomist and progressive lists.

The Aosta Valley, being the smallest region of Italy by area, is not divided into provinces. Nevertheless, it is still divided into 74 comunes namely:

ISTAT code	Municipality	Population (2005)
007001	Allein	243
007002	Antey-Saint-André	602
007003	Aosta / Aoste	34,270
007004	Arnad	1,294
007005	Arvier	848
007006	Avise	312
007007	Ayas	1,296
007008	Aymavilles	1,966
007009	Bard	135
007010	Bionaz	244
007011	Brissogne	962
007012	Brusson	860
007013	Challand-Saint-Anselme	695
007014	Challand-Saint-Victor	589
007015	Chambave	937
007016	Chamois	99
007017	Champdepraz	674
007018	Champorcher	417
007019	Charvensod	2,333
007020	Châtillon	4,846
007021	Cogne	1,470
007022	Courmayeur	2,979
007023	Donnas	2,661
007024	Doues	409
007025	Émarèse	217
007026	Étroubles	472
007027	Fénis	1,653
007028	Fontainemore	412
007029	Gaby	490
007030	Gignod	1,352
007031	Gressan	2,981
007032	Gressoney-La-Trinité	306
007033	Gressoney-Saint-Jean	799
007034	Hône	1,162
007035	Introd	573
007036	Issime	400
007037	Issogne	1,374
007038	Jovençan	709
007039	La Magdeleine	95
007040	La Salle	1,985
007041	La Thuile	766
007042	Lillianes	494
007043	Montjovet	1,795
007044	Morgex	1,938
007045	Nus	2,713
007046	Ollomont	161
007047	Oyace	211
007048	Perloz	467
007049	Pollein	1,441
007050	Pontboset	190
007051	Pontey	742
007052	Pont-Saint-Martin	3,957
007053	Pré-Saint-Didier	968
007054	Quart	3,263
007055	Rhêmes-Notre-Dame	124
007056	Rhêmes-Saint-Georges	200
007057	Roisan	900
007058	Saint-Christophe	3,124
007059	Saint-Denis	361
007060	Saint-Marcel	1,206
007061	Saint-Nicolas	325
007062	Saint-Oyen	218
007063	Saint-Pierre	2,785
007064	Saint-Rhémy-en-Bosses	387
007065	Saint-Vincent	4,833
007066	Sarre	4,434
007067	Torgnon	522
007068	Valgrisenche	184
007069	Valpelline	627
007070	Valsavarenche	178
007071	Valtournenche	2,169
007072	Verrayes	1,305
007073	Verrès	2,623
007074	Villeneuve	1,136
	Total	122,868

Historical population

Year	Pop.	±%
1861	81,884	—
1871	81,260	−0.8%
1881	85,007	+4.6%
1901	83,529	−1.7%
1911	80,680	−3.4%
1921	82,769	+2.6%
1931	83,479	+0.9%
1936	83,455	−0.0%
1951	94,140	+12.8%
1961	100,959	+7.2%
1971	109,150	+8.1%
1981	112,353	+2.9%
1991	115,938	+3.2%
2001	119,548	+3.1%
2011	126,806	+6.1%
2021	123,360	−2.7%
Source: ISTAT

The largest resident foreign-born
groups on 31 December 2019

Nationality	Population
Romania	2,361
Morocco	1,553
Albania	695
China	298
Ukraine	272
Tunisia	261
Dominican Republic	235
France	220
Moldova	179
Algeria	160
Poland	144
United Kingdom	105
Nigeria	102

The population density of Aosta Valley is by far the lowest of the Italian regions. In 2008, 38.9 inhabitants per km were registered in the region, whereas the average national figure was 198.8, though the region has extensive uninhabitable areas of mountain and glacier, with a substantial part of the population living in the central valley.

Negative natural population growth since 1976 has been more than offset by immigration. The region has one of Italy's lowest birth rates, with a rising average age. This, too, is partly compensated by immigration, since most immigrants arriving in the region are younger people working in the tourist industry. Between 1991 and 2001, the population of Aosta Valley grew by 3.1%, which is the highest growth among the Italian regions. With a negative natural population growth, this is due exclusively to positive net migration. Between 2001 and 2011, the population of Aosta Valley grew by a further 7.07%. As of 2006, the Italian National Institute of Statistics (ISTAT) estimated that 4,976 foreign-born immigrants live in Aosta Valley, equal to 4.0% of the total regional population.

The Valdôtain population and their language dialects have been the subject of some sociological research.

The Aosta Valley was the first government authority to adopt Modern French as the official language in 1536, three years before France itself.

Since 1946, Italian and French are the region's official languages and are used for the regional government's acts and laws, though Italian is much more widely spoken in everyday life, and French is mostly spoken in cultural life. Education is conducted evenly in French and Italian, so that anyone who has gone to school in the Aosta Valley can speak both languages to at least a medium-high level.

Legal decree No.365 of 11 November 1946 (art.2) states that it is mandatory to know both Italian and French to teach in Aosta Valley's schools. According to Aosta Valley's autonomous status (art.39), the same quantity of hours of French and Italian teaching must be held. The decree No.861 of the President of the Republic of 31 October 1975 (art.5) states that it is mandatory to pass a French exam to teach in Aosta Valley for Italian native speakers, as well an Italian exam for French native speakers. Italian law No.196 of 16 May 1978 states the adaptation rules of national educational programmes into French for Aosta Valley, and states as well that all members of the examination boards must be fluent both in Italian and French. Aosta Valley students must pass an extra test in French at the Secondary education final exam, similar to the first test (in Italian).

The regional language, known as patoué valdotèn or simply patoué (patois valdôtain in French), is a dialectal variety of Franco-Provençal. It is spoken as a native and second language by 68,000 residents, or about 58% of the population according to a sociolinguistic survey carried out by the Fondation Émile Chanoux in 2001.

The survey found that the Italian language was native to 77.29% of respondents, Franco-Provençal to 17.91%, and French to 1.25%, though the active use of these languages by the population shows French at 75.41% and Franco-Provençal at 55.77%. The population of Gressoney-Saint-Jean, Gressoney-La-Trinité and Issime, in the Lys Valley, speak two dialects of Walser German, Titsch and Töitschu respectively. According to the survey, Walser German was spoken as a mother tongue by 207 people, or 17.78%, in these three villages. Nevertheless, it was known to 56.38% of the population.

There are numerous medieval castles and fortified houses in the Aosta Valley, including Châtel-Argent, Saint-Pierre Castle, Fénis Castle, Issogne Castle, Bard Fort, Ussel Castle, Sarre Castle, Cly Castle, Verrès Castle, and Châtelard Castle. Savoy Castle in Gressoney-Saint-Jean was conceived in the 19th century and completed in 1904. Since 1990, it has also been home to the Savoy Castle Alpine Botanical Garden.

• 
  The Saint-Pierre Castle
• 
  The Sarre Castle [it]
• 
  The Verrès Castle
• 
  The Issogne Castle
• 
  The Bard Fort
• 
  The Savoy Castle
• 
  The Aymavilles Castle [it]
• 
  The Châtel-Argent

The cuisine of Aosta Valley is characterized by simplicity and revolves around "robust" ingredients such as potatoes, polenta; cheese and meat; and rye bread. Many of the dishes involve Fontina, a cheese with PDO status, made from cow's milk that originates from the valley. It is found in dishes such as the soup à la vâpeuleunèntse (Valpelline Soup). Other cheeses made in the region are Tomme de Gressoney and Seras. Fromadzo (Valdôtain for cheese) has been produced locally since the 15th century and also has PDO status.

Regional specialities, besides Fontina, are Motzetta (dried chamois meat), Vallée d'Aoste Lard d'Arnad (a cured and brined fatback product with PDO designation), Vallée d'Aoste Jambon de Bosses (a kind of ham, likewise with PDO designation), a dark bread made with rye, and honey.

Notable dishes include Carbonnade, similar to the Belgian dish of the same name consisting of salt-cured beef cooked with onions and red wine served with polenta; breaded veal cutlets called costolette; teuteuns, salt-cured cow's udder that is cooked and sliced; and steak à la valdôtaine, a steak with croûtons, ham and melted cheese.

Aosta Valley has many small and picturesque villages, three of them have been selected by I Borghi più belli d'Italia (English: The most beautiful Villages of Italy), a non-profit private association of small Italian towns of strong historical and artistic interest, that was founded on the initiative of the Tourism Council of the National Association of Italian Municipalities.

Notable wines include two white wines from Morgex (Blanc de Morgex et de La Salle and Chaudelune), a red wine blend from Arvier (Enfer d'Arvier) and one from Gamay.

• Lillaz

• 
  The prehistoric site near Chenal castle, Montjovet, rich in petroglyphs
• 
  A view from refuge Albert Deffeyes, La Thuile
• 
  Male Alpine Ibex in Gran Paradiso National Park
• 
  Alpine marmot in Gran Paradiso National Park

• Website of the Aosta Valley Regional Authority (in Italian and French)
• Official Tourism website