Events from the year 1870 in art.

• June 28 – Claude Monet marries his mistress and model Camille Doncieux in Paris; Gustave Courbet is a witness.
• July – Franco-Prussian War breaks out: Monet, Pissarro, Daubigny and the dealer Paul Durand-Ruel flee to London; Cézanne and his mistress, Marie-Hortense Fiquet, leave Paris for L'Estaque (on the French Riviera) where he predominantly paints landscapes. In August, Frédéric Bazille joins a Zouave regiment. In September the Dutch painter Lourens Alma Tadema moves permanently to London where he adopts the name Lawrence Alma-Tadema.
• Édouard Manet and Louis Edmond Duranty fight a duel at Café Guerbois, Paris.
• Russian industrialist and patron of the arts Savva Mamontov acquires the Abramtsevo Colony and hosts a group of traditionalist artists there.
• Dante Gabriel Rossetti's Poems are published,^[1] exhumed from Elizabeth Siddal's grave.
• Daoud Corm goes to Rome to study under Roberto Bompiani at the Accademia di San Luca.

• Wilhelm Amberg – Reading from Goethe's Werther (Vorlesung aus Goethes Werther)
• Frédéric Bazille
  • Countryside near Lex
  • Studio in the rue Condamine
  • La Toilette
• Cathy Madox Brown – Ford Madox Brown at his Easel
• Ford Madox Brown – Romeo and Juliet
• Edward Burne-Jones – Phyllis and Demophoon
• Paul Cézanne – Paul Alexis reading a manuscript to Émile Zola (1869–70; São Paulo Museum of Art)
• Edgar Degas
  • The Dancing Class (c.)
  • The Orchestra at the Opera (c.)
• Jean-Jules-Antoine Lecomte du Nouÿ – Demosthenes Practicing Oratory (Démosthène s'exerçant à la parole)
• Henri Fantin-Latour – A Studio in the Batignolles (Musée d'Orsay, Paris)
• Anselm Feuerbach – The Judgement of Paris (c. 1869–70)
• Mariano Fortuny – The Spanish Wedding (Museu Nacional d'Art de Catalunya)
• Jean-Léon Gérôme – Moorish Bath
• Arthur Hughes – You Cannot Barre Love Oute
• Christian Inger - Smith Rescued by Pocahontas
• Jean-Paul Laurens – Pope Formosus and Stephen VI (Le Pape Formose et Étienne VII)
• Édouard Manet
  • La Brioche (Metropolitan Museum of Art, New York)
  • Effect of Snow on Petit-Montrouge (National Museum Cardiff)
• John Everett Millais – The Boyhood of Raleigh (Tate Britain, London)
• Pierre-Auguste Renoir
  • Madame Clémentine Valensi Stora (L'Algérienne)
  • La Promenade
• Dante Gabriel Rossetti
  • Beata Beatrix (approximate completion date)
  • Sibylla Palmifera
• Dmitri Sinodi-Popov – An Old Greek
• James Tissot
  • Captain Frederick Gustavus Burnaby
  • La Partie carrée
• Raja Ravi Varma – Shakuntala

• Statue of Abraham Lincoln (New York City)

• Grand Prix de Rome, painting:
• Grand Prix de Rome, sculpture:
• Grand Prix de Rome, architecture: Albert-Félix-Théophile Thomas.
• Grand Prix de Rome, music: Charles Edouard Lefebvre & Henri Maréchal

• January 1 – Louis Vauxcelles, French Jewish art critic (died 1943)
• January 11 – Alexander Stirling Calder, American sculptor (died 1945)
• February 5 – C. E. Brock, English painter and illustrator (died 1938)
• March 13 – William Glackens, American painter (died 1938)
• June 22 – Antonio Dattilo Rubbo, Italian-born painter and art teacher (died 1955)
• July 21 – Emil Orlík, Czech-born painter and lithographer (died 1932)
• July 25 – Maxfield Parrish, American painter and illustrator (died 1966)
• November 18 – Franz Metzner, German sculptor (died 1919)
• November 25 – Maurice Denis, French painter and decorative artist (died 1943)
• December 23 – John Marin, American painter (died 1953)
• date unknown – Arthur Diehl, English-born landscape painter (died 1929)

• January 17 – Alexander Anderson, American illustrator (born 1775)
• January 27 – Johannes Flintoe, Danish-Norwegian painter of Norwegian landscapes (born 1787)
• February 21 – Robert Jefferson Bingham, English-born photographer (born 1824 or 1825)
• March 19 – William Egley, English miniature painter (born 1798)
• April 25 – Daniel Maclise, Irish-born painter (born 1806)
• May 17 – David Octavius Hill, Scottish painter and pioneer photographer (born 1802)
• July 13 – Christian Albrecht Jensen, Danish painter (born 1792)
• August 25 – Richard Seymour-Conway, 4th Marquess of Hertford, English francophile art collector (born 1800)
• November 7 – Cornelia Aletta van Hulst, Dutch painter (born 1797)
• November 28 – Frédéric Bazille, French Impressionist painter (born 1841) (killed in action)
• December 9
  • Max Emanuel Ainmiller, German glass painter (born 1807)
  • Patrick MacDowell, Irish sculptor from Belfast (born 1799)
• December 12 – Martin Cregan, Irish portrait painter (born 1788)
• Undated – Achille Leonardi, Italian genre painter (born 1800)