Events from the year 1866 in art.

• July 28 – 18-year-old Vinnie Ream is commissioned by the United States Congress to make a marble statue of Abraham Lincoln for the United States Capitol rotunda in Washington, D.C.
• Nationalmuseum opens in new premises in Stockholm, Sweden, under this name.
• Théophile Thoré-Bürger publishes the first catalogue raisonné of Vermeer's paintings, in the Gazette des Beaux-Arts, bringing him to international prominence after nearly two centuries. ^[1]

• Albert Bierstadt – A Storm in the Rocky Mountains, Mt. Rosalie
• Carl Bloch – In a Roman Osteria
• Odoardo Borrani – At the Chorus
• Edward Burne-Jones – The Princess Sabra Led to the Dragon
• Julia Margaret Cameron – photographs
  • The Mountain Nymph Sweet Liberty
  • Series of Life Sized Heads
• Paul Cézanne – Portrait of Louis-Auguste Cézanne, Father of the Artist, reading l'Evénement ( National Gallery of Art, Washington, D.C.)
• Jean-Baptiste-Camille Corot – Agostino (National Gallery of Art, Washington, D.C.)
• Gustave Courbet
  • L'Origine du monde
  • Le Sommeil
• Edgar Degas – Scene from the Steeplechase: The Fallen Jockey (reworked in 1880-1881 and again c. 1897)
• Gustav Doré (woodcuts)
  • Illustrations for La Grande Bible de Tours
  • Illustrations for Milton's Paradise Lost
• Giovanni Fattori – La Rotonda di Palmieri
• Jean-Léon Gérôme
  • Cleopatra and Caesar
  • The Slave Market (approximate date)
• Francesco Hayez – Odalisque with Book
• David Octavius Hill – The First General Assembly of the Free Church of Scotland, Signing the Act of Separation and Deed of Demission at Tanfield, Edinburgh 23 May 1843 (completed)
• Winslow Homer – Prisoners from the Front ( Metropolitan Museum of Art, New York)
• Sir Edwin Landseer – The Arab Tent ( Wallace Collection, London; approximate date)
• August Malmström – Dancing Fairies
• Édouard Manet
  • The Fifer ( Musée d'Orsay, Paris)
  • A King Charles Spaniel (National Gallery of Art, Washington, D.C.)
  • Still Life with Melon and Peaches (National Gallery of Art, Washington, D.C.)
  • Woman with a Parrot (Metropolitan Museum of Art, New York)
• Jan Matejko – Rejtan, or the Fall of Poland
• Claude Monet
  • Camille (The Woman in the Green Dress)
  • Le déjeuner sur l’herbe
  • Women in the Garden (begun)
• Albert Joseph Moore
  • The Last Supper and The Feeding of the Five Thousand (on chancel walls of church of St. Alban's, Rochdale; completed)
  • The Shunamite relating the Glories of King Solomon to her Maidens
• Dante Gabriel Rossetti – The Beloved
• Rebecca Solomon – A Wounded Dove
• Simeon Solomon – Love in Autumn
• Bertalan Székely – The Battle of Mohács
• Frederick Walker – Wayfarers
• John Quincy Adams Ward – Indian Hunter (bronze)

• January 17 – Joseph Bernard, French sculptor (died 1931)
• January 23 – Lydia Field Emmet, American painter and designer (died 1952)
• March 17 – Alice Austen, American photographer (died 1952)
• June 13 – Aby Warburg, German art historian (died 1929)
• June 16 – Joaquín Clausell, Mexican impressionist landscape painter, lawyer and political activist (died 1935)
• July 3 – Ambroise Vollard, French art dealer (died 1939)
• July 14 – Juliette Wytsman, Belgian painter (died 1925)
• July 19 – John Duncan, Scottish painter (died 1945)
• July 28 – Beatrix Potter, English writer and illustrator (died 1943)
• August 9 – Emil Fuchs, Austrian-born sculptor and painter (died 1929)
• August 13 – Jadwiga Golcz, Polish photographer (died 1936)
• August 31 – Georg Jensen, Danish silversmith (died 1935)
• October 2 – Charles Ricketts, English designer (died 1931)
• unknown date – Milly Childers, English painter (died 1922)

• January 15 – Massimo d'Azeglio, Italian statesman, novelist and painter (born 1798)
• January 17 – George Petrie, Irish painter, musician, antiquary and archaeologist (born 1790)
• January 27 – John Gibson, Welsh-born sculptor (born 1790)
• January 30 – Léon Bonvin, French painter an watercolorist (born 1834)
• March 23 – Ferdinand von Arnim, German architect and watercolour painter (born 1814)
• April 1 – Chester Harding, American portrait painter (born 1792)
• April 3 – Frederick William Fairholt, English engraver (born 1814)
• April 7 – Thomas Musgrave Joy, English portrait painter (born 1812)
• April 17 – Carl Georg Enslen, Austrian painter (born 1792)
• April 24 – Giuseppe Tominz, Austrian portrait painter (born 1790)
• April 26 – Hermann Goldschmidt, German-born painter and astronomer (born 1802)
• June 8 – William Bewick, English portrait painter (born 1795)
• June 14 – John Hayes, English portrait-painter (born 1786)
• August 9 – Raffaello Sernesi, Italian painter and medallist (born 1838)
• September 10 – David Hay, British interior decorator (born 1798)
• November 23 – Paul Gavarni (Sulpice Guillaume Chevalier), French caricaturist (born 1801/1804)
• December 20 – Jacobus Cornelis Gaal, Dutch painter and etcher (born 1796)
• date unknown – Jean Henri De Coene, Belgian painter of genre and historical subjects (born 1798)