The year 1911 in science and technology involved some significant events, listed below.

• June 28 – The Nakhla meteorite (from Mars) lands in the area of Alexandria, Egypt, purportedly killing a dog.^[1]

• May 19 – Parks Canada, the world's first national park service, is established as the Dominion Parks Branch under the Department of the Interior.
• July 7 – The United States, Russia, the United Kingdom and Japan, meeting in Washington, D.C., sign the North Pacific Fur Seal Convention of 1911, prohibiting open-water seal hunting of the endangered fur seal in the North Pacific Ocean,^[2] the first international treaty to address wildlife conservation issues. In the next six years, the seal population increases by 30%.^[3]

• January 3 – 1911 Kebin earthquake: An earthquake of 7.7 moment magnitude strikes near Almaty in Russian Turkestan.^[4]

• July 24 – American explorer Hiram Bingham III rediscovers the Inca citadel of Machu Picchu, Peru, and introduces it to the world.
• December 14 – Norwegian explorer Roald Amundsen and a team of four become the first people to reach the South Pole.

• Robert Remak's doctoral dissertation Über die Zerlegung der endlichen Gruppen in indirekte unzerlegbare Faktoren establishes that any two decompositions of a finite group into a direct product are related by a central automorphism.
• Traian Lalescu publishes Introduction to the Theory of Integral Equations, the first ever monograph on the subject of integral equations.

• Eugen Bleuler expands on his definition of schizophrenia as a condition distinct from Dementia praecox, in Dementia Praecox oder Gruppe der Schizophrenien.^[5][6][7]

• April 8 – Heike Kamerlingh Onnes discovers the phenomenon of superconductivity.^[8]
• June 24–30 – Domenico Pacini runs a series of measurements of underwater ionization in the Gulf of Genoa, demonstrating that the radiation later recognised as cosmic rays cannot be originated by the Earth's crust.
• October – The first Solvay Congress of physicists convenes.
• Ernest Rutherford explains the Geiger–Marsden experiment and derives the Rutherford cross section by deducing the existence of a compact atomic nucleus from scattering experiments. He proposes the Rutherford model of the atom and demonstrates that J. J. Thomson's plum pudding model is incorrect.
• Charles Wilson finishes a sophisticated cloud chamber.

• The Ponzo illusion, a geometrical-optical illusion, is first demonstrated by Italian psychologist Mario Ponzo.^[9]

• January 18 – Eugene Ely lands on the deck of the USS Pennsylvania anchored in San Francisco Bay, the first aircraft landing on a ship.
• June 5 – Charles F. Kettering files a United States patent for an electric starter motor.^[10]
• November 4 – MS Selandia, the first large ocean-going diesel ship, is launched in Denmark; Ivar Knudsen is the diesel engineer. The 1909-launched Dutch diesel tanker Vulcanus also enters service this year.
• John Joseph Rawlings files a United Kingdom patent for a wall plug.^[11]
• The Lewis automatic light machine gun is invented by United States Army Colonel Isaac Newton Lewis, based on initial work by Samuel Maclean.^[12]

• March–May – A serialized version of Frederick Winslow Taylor's monograph The Principles of Scientific Management^[13] appears in The American Magazine, boosting the efficiency movement.

• Nobel Prizes
  • Physics – Wilhelm Wien
  • Chemistry – Marie Curie^[14]
  • Medicine – Allvar Gullstrand

• January 26 – Polykarp Kusch (died 1993), German-born molecular physicist, winner of the Nobel Prize in Physics.
• February 14 – Willem Johan Kolff (died 2009), Dutch inventor of hemodialysis.
• March 26 – Bernard Katz (died 2003), German-born biophysicist, winner of the Nobel Prize in Physiology or Medicine.
• April 3 – Michael Woodruff (died 2001), English pioneer of organ transplant surgery.
• April 6 – Feodor Lynen (died 1979), German biochemist, winner of the Nobel Prize in Physiology or Medicine.
• April 8 – Melvin Calvin (died 1997), American biochemist, winner of the Nobel Prize in Chemistry.
• April 16 – William T. Stearn (died 2001), English botanist.
• April 18 – Maurice Goldhaber (died 2011), Austrian-born physicist.
• May 22 – Anatol Rapoport (died 2007), Russian-born mathematical psychologist.
• June 13 – Luis Alvarez (died 1988), American experimental physicist, winner of the Nobel Prize in Physics.
• June 25 – William Howard Stein (died 1980), American biochemist, winner of the Nobel Prize in Chemistry.
• July 3 – Herbert E. Grier (died 1999), American electrical engineer.
• July 4 – Frederick Seitz (died 2008), American solid-state physicist.
• July 5 – Emil L. Smith (died 2009), American biochemist studying protein structure and function and biochemical evolution.
• July 9 – John A. Wheeler (died 2008), American theoretical physicist.
• August 9 – William A. Fowler (died 1995), American nuclear and astrophysicist, winner of the Nobel Prize in Physics.
• August 29 – John Charnley (died 1982), English orthopaedic surgeon.
• September 29 – R. V. Jones (died 1997), English physicist, expert in electronic military defence.
• October 5 – Pierre Dansereau (died 2011), French Canadian ecologist.
• November 27 – Fe del Mundo (died 2011), Filipino pediatrician and National Scientist of the Philippines.
• December 14 – Hans von Ohain (died 1998), German aeronautical engineer.
• December 23 – Niels Kaj Jerne (died 1994), English-born Danish immunologist, winner of the Nobel Prize in Physiology or Medicine.

• January 17 – Sir Francis Galton (born 1822), English explorer and biologist.
• February 15 – Theodor Escherich (born 1857), German-born pediatric bacteriologist.
• March 1 – Jacobus van 't Hoff (born 1852), Dutch chemist.
• May 21 – Williamina Fleming (born 1857), American astronomer.^[15]
• May 24 – Ernst Remak (born 1849), German neurologist.
• June 26 – Signe Häggman (born 1863), Finnish pioneer of physical education of disabled people.
• December 2 – George Davidson (born 1825), English-born geodesist, astronomer, geographer, surveyor and engineer in the United States.
• December 10 – Joseph Dalton Hooker (born 1817), English botanist.
• December 13 (O.S. November 30) – Nikolay Beketov (born 1827), Russian chemist.