1912 (MCMXII) was a leap year that began on a Monday in the Gregorian calendar and a leap year that began on a Sunday in the Julian calendar.
January 1 - Chinese First President Sun Yat-sen is forced to step down in favor of Commander-in-Chief Yuan Shikai.
January 3 - The Swedish Scout Association is formed
January 6 - New Mexico becomes the 47th state to join the United States.
January 8 - African National Congress (ANC) is formed in South Africa.
January 14 - In opposition to the decision to suspend the construction of a Swedish armored boat, churchman Manfred Björkquist starts a fundraiser for one.
January 15 - Sven Hedin's post on the Swedish defense issue, A word of warning, is published and distributed in one million copies.
January 17 - Robert Scott arrives at the South Pole, a month after Roald Amundsen, and freezes to death on the way back.
January 22 - August Strindberg is greeted on his 63rd birthday by 10,000 people in a torchlight procession outside his home. He receives an alternative Nobel Prize after a collection.
January 26 - Another fundraiser, the Swedish Armored Boat Association, is formed to raise money for a Swedish armored boat.
February 13 - In the face of civil war threats, Chinese regent Chun relinquishes his son Pu Yi's imperial title, and the Chinese government declares a republic. Sun Yat-sen withdraws and the Imperial Prime Minister becomes China's first president.
February 14 - Arizona becomes the 48th state to join the United States.
February 22 - The aircraft manufacturer Fokker is founded.
February 23 - 5-year-old Karl Gunnar Åberg becomes one of the Carnegie Foundation's first heroes as he has saved his siblings in a fire.
March 2 - The collected Swedish national gift of SEK 45,000 is handed over to August Strindberg.
March 5 - 500 people die when the Spanish steamboat "Principe de Asturias" goes on a cliff.
April 2 - The Swedish government presents a proposal for women's suffrage, which is, however, stopped by FK.
April 6 - The cinematographer Svea in Sundsvall, which has so far been housed in temporary premises, is inaugurated at its current location in a cinema palace designed by Ragnar Östberg.
April 14-15 - The British passenger ship Titanic sinks after colliding with an iceberg in the Atlantic Ocean about 600 kilometers off Newfoundland while traveling between Southampton and New York. 2227 people are on board, of these 1522 die. About 130 Swedes are on board, of which 90 die.
April 28 - A charity matinee is arranged in Stockholm for the Swedish victims of the Titanic disaster.
May 1 - Russian socialist and future Soviet ambassador Aleksandra Kollontaj speaks in May at Gärdet in Stockholm.
May 5 - The first issue of the Russian Communist newspaper Pravda is published.
May 7 - After a national rally, the Swedish Armored Boat Association hands over just over SEK 10 million to the King and Prime Minister of Sweden.
May 8 - Sweden's Riksdag decides to establish the National Board of Health and Welfare from January 1, 1913.
May 14 - At the death of Frederick VIII, he is succeeded as King of Denmark by his son Christian X.
May 18 - The proposal for female Swedish suffrage falls on the opposition of the First Chamber.
May 19 - August Strindberg is buried, and large crowds line the procession road. Nathan Söderblom is the officiant at the funeral, which takes place at "Nya kyrkogården" (Northern cemetery) in Stockholm.
May 22 - The Russian daily Pravda publishes its first issue.
May 24 - The Social Democrat Carl Lindhagen's motion to introduce a republic in Sweden is rejected in AK with the votes 118-12. According to Hjalmar Branting, the question of the establishment of a republic "is not currently relevant".
Stockholm Stadium is inaugurated, designed by Torben Grut, ahead of the Olympic Games. The construction has cost SEK 1,188,000.
The first mail flight in Sweden takes place between Eslöv and