The year 1556 CE in science and technology included a number of events, some of which are listed here.

• January 23 – Shaanxi earthquake in China.^[1]
• February – Great Comet of 1556 becomes visible in Europe.^[2]
• Publication of Georgius Agricola's textbook on metal mining and processing, De re metallica (posthumously, at Basel).^[3]
• Minas de Ríotinto in Huelva, Andalusia, rediscovered.

• Publication in Rome of Juan Valverde de Amusco's Historia de la composicion del cuerpo humano, including Realdo Colombo's discovery of pulmonary circulation.
• Publication of the standard reference work on marine animals, Libri de piscibus marinis in quibus verae piscium effigies expressae sunt by Guillaume Rondelet, Chancellor of the University of Montpellier; his anatomical drawing of a sea urchin is the earliest extant depiction of an invertebrate.^[4] Rondelet's Methodus de materia medicinali et compositione medicamentorum Palavii is also published.
• Cholera outbreak in Oran.

• February 21 – Sethus Calvisius, German musician and astronomer (died 1615)
• August 24 – Sophia Brahe, Danish astronomer (died 1643)

• November 10 – Richard Chancellor, English Arctic explorer (drowned at sea) (born c. 1521)
• 'Denis Zachaire', French alchemist (born 1520)