The following events occurred in June 1903:

• Born: Vasyl Velychkovsky, Ukrainian bishop and martyr, in Stanislav (died 1973)

• An earthquake of 6.9 magnitude struck the Alaska Peninsula, part of the territory of the United States.

• English artist Laura Johnson married painter Harold Knight.^[1]

• Sir Edward Elgar conducted his oratorio, The Dream of Gerontius, at Westminster Cathedral, the first time it had been performed in London.
• Born: Aram Khachaturian, Armenian composer, in Tiflis, Russian Empire (died 1978)

• Born: Marguerite Yourcenar, Belgian-French author, in Brussels (died 1987)

• Trinity College, Dublin, announced its intention to accept women as full members in the following year. "Steamboat ladies" from Oxford and Cambridge would be among the first recipients.^[2]
• Died: Gaspar Núñez de Arce, 68, Spanish poet

• Born: Theo Lingen, German actor (d. 1978)

• Harry Vardon of Jersey won the 1903 Open Championship golf tournament at Prestwick in Scotland.^[3]
• Died:
  • King Alexander I of Serbia, 26, and his wife Queen Draga, 38, both shot dead in a coup d'état in Belgrade by conspirators from the Black Hand (Crna Ruka) society.^[4]
  • Nikolai Bugaev, 65, Russian mathematician

• Italy's Prime Minister, Giuseppe Zanardelli, resigned after losing a vote in the Italian Chamber of Deputies; he reconsidered, and would remain in the post until November.^[5]

• Heppner flood of 1903: The town of Heppner, Oregon, was nearly destroyed by a cloud burst that resulted in a flash flood that killed an estimated 247 people.^[6]

• In Germany's federal election, the Social Democratic Party (SPD) won the popular vote, but the Centre Party remained the largest party in the Reichstag.^[7]
• In the Danish Folketing election, the Venstre Reform Party, under incumbent Council President Johan Henrik Deuntzer, won 73 of the 114 seats.^[8]
• Norwegian explorer Roald Amundsen set off from Oslo in an attempt at the first east-west navigation of the Northwest Passage.^[9]
• The Ford Motor Company was incorporated in Detroit by Henry Ford.^[10]

• The British ironclad turret ship HMS Scorpion foundered in the Atlantic Ocean while being towed from the United Kingdom to the United States to be scrapped, and was lost.^[11] The Royal Navy ship had already been decommissioned, sunk as a target, and raised for its scrap value.

• Born:
  • Jeanette MacDonald, US singer and actress, in Philadelphia (died 1965)
  • Raymond Radiguet, French author, in Saint-Maur (died 1923)

• The United States military officially adopted the M1903 Springfield rifle.
• A minor earthquake (4.9 magnitude) struck an area of North Wales, UK, centred on the town of Caernarfon.^[12]
• Born:
  • Lou Gehrig, American baseball player, in New York City (died 1941)^[13]
  • Wally Hammond, English cricketer, in Dover (died 1965)
• Died: Herbert Vaughan, 71, English Catholic cardinal and Archbishop of Westminster

• US magazine The Saturday Evening Post began its serialization of Jack London's third novel, The Call of the Wild.

• Born:
  • Al Hirschfeld, US caricaturist, in St Louis (died 2003)
  • Alf Sjöberg, Swedish theatre and film director, in Stockholm (died 1980)

• Born:
  • John Dillinger, US gangster, in Indianapolis (died 1934)
  • Jiro Horikoshi, Japanese aircraft designer, in Fujioka (died 1982)
  • Ben Pollack, US jazz drummer and bandleader, in Chicago (died 1971)

• Nadir of American race relations: George White, an African-American suspected of murdering Helen Bishop, a minister's daughter, was lynched in New Castle County, Delaware, United States.^[14]
• Born: Anthony Veiller, US screenwriter and film producer, son of screenwriter Bayard Veiller and actress Margaret Wycherly, in New York City (died 1965)

• Born:
  • Pierre Brossolette, French journalist and resistance fighter, in Paris (died 1944)
  • George Orwell, English author, in Motihari, Bengal Presidency, British India, under the name Eric Arthur Blair (died 1950)

• 19-year-old American socialite Aida de Acosta became the first woman to fly a powered aircraft solo when she piloted Santos-Dumont's motorized dirigible, "No. 9", from Paris to Château de Bagatelle in France.^[15]
• Elisabeth Moore (US) won the Women's Singles competition at the 1903 U.S. National Championships tennis tournament.^[16]

• A meteorite fall, classification H5, was observed in Uberaba, Minas Gerais, Brazil.
• Willie Anderson of Scotland won the U.S. Open golf tournament.^[17]
• Born: Alan Blumlein, British electronics engineer, in London (died 1942)

• A meteorite fall, classification L6, was observed in Rich Mountain (Watauga County, North Carolina), United States.