1440

1440 (MCDXL) was a leap year starting on Friday of the Julian calendar, the 1440th year of the Common Era (CE) and Anno Domini (AD) designations, the 440th year of the 2nd millennium, the 40th year of the 15th century, and the 1st year of the 1440s decade. As of the start of 1440, the Gregorian calendar was 9 days ahead of the Julian calendar, which was the dominant calendar of the time.

• February 21 - The Prussian Confederation is formed.
• September - Gilles de Rais, an early known serial killer, is arrested and taking into custody on orders from the Bishop of Nantes.

• January 22 - Ivan III of Russia (d. 1505)
• February 10 - Henry of York, elder brother of Edward IV of England and Richard III of England (died 1441)
• February 22 - King Ladislaus Posthumus of Bohemia and Hungary (died 1457)
• Pedrarias Davila, Spanish colonial administrator (died 1531)
• Kabir, Indian mystic (died 1518)
• Jorge Manrique, Spanish poet (died 1479)

• September 30 - Reginald Grey, 3rd Baron Grey de Ruthyn (born c.1362)
• October 26 - Gilles de Rais, Marshal of France (born 1405)