Lake Como (Italian: Lago di Como [ˈlaːɡo di ˈkɔːmo], locally [ˈkoːmo]), also known as Lario, is a lake of glacial origin in Lombardy, Italy.

It has an area of 146 square kilometres (56 sq mi), making it the third-largest lake in Italy, after Lake Garda and Lake Maggiore. At over 400 metres (1,300 ft) deep, it is the fifth-deepest lake in Europe and the deepest outside Norway; the bottom of the lake is 227 metres (745 ft) below sea level. One notable characteristic is its distinctive "Y" shape.

Lake Como has been a popular retreat for aristocrats and wealthy people since Roman times, and a very popular tourist attraction with many artistic and cultural gems. It has many villas and palaces such as Villa Olmo, Villa Serbelloni and Villa Carlotta. Many famous people have owned homes on the shores of Lake Como, including George Clooney, Madonna and Donatella Versace.

In 2014, The Huffington Post described it as the most beautiful lake in the world for its microclimate and environment with prestigious villas and villages.

The lake's official name is Lario (derived from the Latin Larius), but it is rarely used informally, while it is still used in formal language; it is also found in the toponym of some villages along the lake such as Pognana Lario and Mandello del Lario; Italians usually call it Lago di Como.

The lake is shaped much like an inverted letter "Y". The northern branch begins at the town of Colico, while the towns of Como and Lecco sit at the ends of the southwestern and southeastern branches respectively. The small towns of Bellagio, Menaggio and Varenna are situated at the intersection of the three branches of the lake: a boat service operates a triangular route between them.

Lake Como is fed primarily by the Adda, which enters the lake near Colico and flows out at Lecco. This geological conformation makes the southwestern branch a dead end, and so Como, unlike Lecco, is sometimes flooded.

The mountainous pre-alpine territory between the two southern arms of the lake (between Como, Bellagio and Lecco) is known as the Larian Triangle, or Triangolo lariano. The source of the river Lambro is here. At the centre of the triangle, the town of Canzo is the seat of the Comunità Montana del Triangolo lariano, an association of the 31 municipalities that represent the 71,000 inhabitants of the area.

Lake Como
Climate chart (explanation)
J F M A M J J A S O N D     79     6 −2     74     8 −1     109     13 4     157     17 7     201     23 12     175     27 16     137     30 19     173     29 19     160     23 13     147     19 9     127     12 4     66     9 2 █ Average max. and min. temperatures in °C █ Precipitation totals in mm
Imperial conversion J F M A M J J A S O N D     3.1     43 28     2.9     46 30     4.3     55 39     6.2     63 45     7.9     73 54     6.9     81 61     5.4     86 66     6.8     84 66     6.3     73 55     5.8     66 48     5     54 39     2.6     48 36 █ Average max. and min. temperatures in °F █ Precipitation totals in inches

According to the Köppen climate classification, the Lake Como area is categorized as humid subtropical climate; average temperatures range from 4 °C (39 °F) in January to 25 °C (77 °F) in July. Water temperatures reach an average of 26 °C (79 °F) in July.

• Winter – The lake helps to maintain a mild average temperature (7 °C; 45 °F) in the surrounding region; snowfall is erratic and occurs mainly at higher elevations; from time to time, periods of frost from the Siberian Anticyclone have been observed.
• Spring and Autumn – These seasons are well marked and pleasant, with average daytime temperatures around 17 °C (63 °F), and are distinguished by increased precipitation.
• Summer – During this season average daytime temperatures hover above 27 °C (81 °F) and heatwaves have been recurring in recent years with temperatures reaching as high as 38 °C (100 °F), so summer can be quite hot and muggy. This season is also subject to thunderstorms and, at times, violent hailstorms.

Until the late 20th century winters used to be quite snowy and cold, with average daily temperatures well below freezing in January and February; however, due to global warming, average temperatures in winter have gradually risen since the turn of the 21st century, reaching a record high of 21 °C (70 °F) on January 27, 2024; until the late 2000s summers as well used to be distinguished by pleasant climate but since the 2010s average temperatures have been constantly rising and once rare severe weather events, such as rainstorms and hailstorms, have been happening with increased frequency.

At the beginning of the first millennium B.C. during the Iron Age, the Comum oppidum was born and the civilization of Como developed, inserted in the broader Golasecca culture. In 196 B.C. the army of the consul Claudius Marcellus defeats the Celts tribe of the Comenses and conquered the city. Comum was then strengthened and rebuilt after a raid by Rhaetian and repopulated with 3,000 settlers in 77 B.C. Finally, after having reclaimed the marshy area, in 59 B.C. it was re-founded with the name of Novum Comun in its current location on the lake shore at the behest of Gaius Julius Caesar. Pliny the Younger, in one of his Epistulae, describes the lake and its surrounding area as providing plentiful opportunities for fishing and hunting. According to the Notitia Dignitatum, at least since the 4th century, a Praefectus commanding a Roman military fleet was present on the lake.

During the Middle Ages and the Renaissance, the waters of the lake were the scene of military clashes, such as in the 12th century during the war of Milan against Como, which saw the Como fleet in action against the ships of the Milanese and their allies or between 1525 and 1532 due to the Musso war unleashed by Gian Giacomo Medici.

On 28 April 1945, deposed Italian dictator Benito Mussolini was executed in the lakeside village of Giulino, about 180 m (590 ft) from the waterfront.

As a tourist destination, Lake Como is popular for its landscapes, wildlife and spas. It is a venue for sailing, windsurfing and kitesurfing.

Although generally considered safe, bathers aiming to find relief from the heat and swimming enthusiasts alike should exercise caution, as a prevailing regulation prohibits diving and swimming both in the city of Como and in the various small villages along the lake. Exceptions are found only in privately managed lidos or designated public beaches where explicit signage permits swimming activities. This prohibition stems from the danger posed by the lake's waters that swiftly transition from shallow to deep near the shoreline and from unpredictable aquatic conditions, which have led to numerous incidents, including drowning cases attributed to sudden thermal shock.

The lake is well known for the attractive villas that have been built there since Roman times when Pliny the Younger built the Comedia and the Tragedia resorts. Many villas on the lake shores have admirable gardens that benefit from the mild climate induced by the stabilizing presence of 22.5 cubic kilometres (5.4 cu mi) of lake water and can sustain many subtropical and Mediterranean plants.

Villa Carlotta was built for the Milanese Marquis Giorgio Clerici in 1690 and occupies a site of over 7 ha (17 acres) at Tremezzo, facing the Bellagio peninsula. An Italian garden (with steps, fountains and sculptures) was laid out at the same time. The villa was later sold to powerful banker and Napoleonic politician Giovanni Battista Sommariva. Stendhal was his guest in 1818, and his visit is recalled at the start of La Chartreuse de Parme. In 1843 it was purchased by Princess Marianne of Nassau as a wedding present for her daughter Carlotta, after whom the villa is now named. The latter, together with her husband Georg II of Saxen-Meiningen, laid out the woodland landscape park in Romantic style. The villa today includes a museum of agricultural implements as well as important works of sculpture by Sommariva's friend Antonio Canova and by Luigi Acquisti.

Villa d'Este, in Cernobbio, was built in 1568 by Cardinal Tolomeo Gallio, a native of the town. In 1816–1817 the villa was home to Caroline of Brunswick, estranged wife of the Prince of Wales and shortly to become queen consort of King George IV of the United Kingdom. The landscaped gardens in the English style are a product of this period. Later in the century, it was turned into a luxury hotel. Today the Villa d'Este is known for attracting celebrity guests.

Villa del Balbianello, famous for its elaborate terraced gardens, lies on a promontory of the western shore of the lake near Isola Comacina. Built in 1787 on the site of a Franciscan monastery, it was the home of explorer Guido Monzino and today houses a museum devoted to his work.

Villa Melzi d'Eril in Bellagio was built in neo-classical style by architect Giocondo Albertolli in 1808–1810 as the summer residence of Duke Francesco Melzi d'Eril, who was vice-president of the Napoleonic Italian Republic. The park includes an orangery, a private chapel, fine statues and a Japanese garden, and is planted, as often on Lake Como, with huge rhododendrons. Nineteenth-century guests at the Villa included Stendhal and Franz Liszt.

Villa Serbelloni, also in Bellagio, hosts the Rockefeller Foundation Bellagio Center, a 50-acre (200,000 m) international conference centre set up and managed by the Rockefeller Foundation since 1959, which also operates a "scholar-in-residence" program for scholars from around the world. This is believed to have been the site of Pliny the Younger's villa "Tragedia". Its well-known park was created at the end of the 18th century by Alessandro Serbelloni.

Many famous people have or have had homes on the shores of Lake Como, such as George Clooney.

Lake Como is served by a public transport system connecting the various villages on the lake. A motorized service began in 1826 when a steamship with sails, the Lario, was launched by the newly established Società privilegiata per l'impresa dei battelli a vapore nel Regno Lombardo Veneto. Since 1952 the fleet has been managed by a government organisation named Gestione Commissariale Governativa and later Gestione Governativa Navigazione Laghi, which is also responsible for transport services on Lake Maggiore and Lake Garda.

There exist three primary services:

• Motorship services along the western branch and north towards Colico and back to Como, with additional shuttles to the mid-lake area;
• Fast services that broadly follow the same route but with fewer stops; the service, which is more expensive, is operated by hydrofoils;
• Ferries able to carry passengers and cars across the popular tourist destinations Menaggio, Bellagio, Varenna and Cadenabbia.

The Sacro Monte di Ossuccio ("Holy Mount of Ossuccio") is a sanctuary located on a hillside slope between olive groves and woods along the western edge of Lake Como facing Isola Comacina. Fifteen Baroque-inspiredchapels, built between 1635 and 1710, and dedicated to the Mysteries of the Rosary are dotted along the way that leads to the Monastery. This building is the last in the chain and is dedicated to the Coronation of the Virgin.

In 2003, the Sacri Monti of Piedmont and Lombardy, including that of Ossuccio, were added by UNESCO to the World Heritage List.

Cities and villages on Lake Como

Western shore from North to South	South shore from West to East	Eastern shore from North to South
Domaso Gravedona Dongo Musso Menaggio Cadenabbia Griante Tremezzo Mezzegra Lenno Ossuccio Sala Comacina Colonno Argegno Brienno Moltrasio Cernobbio Como	Como Blevio Brunate Torno Nesso Bellagio Oliveto Lario Malgrate Lecco	Colico Dorio Dervio Bellano Varenna Lierna Mandello del Lario Abbadia Lariana Lecco

Lake Como attracts visitors from around the world and as a consequence, the economy of the towns surrounding Lake Como is predominantly dependent on tourism and related activities. The tourism sector stimulates local businesses, including hospitality, restaurants and retail, while also fostering the growth of ancillary services such as transportation, cultural tours and recreational activities. This reliance on tourism has led to significant investments in infrastructure and amenities to accommodate and enhance the visitor experience, making it a vital component of the regional economy.

• Letitia Elizabeth Landon's poem The Lake of Como was published in Fisher's Drawing Room Scrap Book, in 1837. It illustrates a painting by Samuel Prout, engraved by William Miller.

• In 1818 Percy Bysshe Shelley wrote to Thomas Love Peacock: "This lake exceeds anything I ever beheld in beauty, except the arbutus islands of Killarney. It is long and narrow, and has the appearance of a mighty river winding among the mountains and the forests."

• Several scenes from the 2002 film Star Wars: Episode II – Attack of the Clones were filmed at Lake Como.

• Italian Lakes
• List of lakes of Italy

• Coolidge, William Augustus Brevoort (1911). "Como, Lake of" . Encyclopædia Britannica. Vol. 6 (11th ed.). p. 794.
• Macadam, Alta (1997). Blue Guide. Northern Italy: From the Alps to Bologna. London: A & C Black. ISBN 0-7136-4294-7.

• Villacarlotta.it, Villa Carlotta