The year 1678 in science and technology involved some significant events.

Astronomy

• Edmund Halley publishes a catalogue of 341 southern stars—the first systematic southern sky survey.

Physics

• Christiaan Huygens publishes his Traité de la Lumière/Treatise on Light, which states his principle of wavefront sources.
• Robert Hooke discovers the fundamental law of elasticity when he finds that the stress (force) exerted is proportional to the strain (elongation) produced.

Zoology

• Publication of English Spiders by Martin Lister, the first book devoted to spiders.

Births

• April 14 – Abraham Darby I, ironmaster (died 1717)
• July 16 – Jakob Hermann, mathematician (died 1733)
• October 27 – Pierre Raymond de Montmort, mathematician (died 1719)
• November 26 – Jean-Jacques d'Ortous de Mairan, geophysicist (died 1771)
• December 2 – Nicolaas Kruik (Cruquius), cartographer and meteorologist (died 1754)
• unknown – Pierre Fauchard, physician and "father of modern dentistry" (died 1761)

Deaths

• November 28 – Willem Piso, physician and naturalist (born 1611)