The year 1698 in science and technology involved some significant events.

• Christiaan Huygens, in his posthumously published book Kosmotheoros, argues that other planets in the Solar System could contain extraterrestrial life, starting a debate that extends into the 21st century.

• November – HMS Paramour sets sail under the command of Edmond Halley on the first purely scientific voyage by an English naval vessel, to investigate magnetic declination.

• January 11 – April 21 – Tsar Peter the Great of Russia (incognito as 'Peter Mikhailov') visits England as part of his Grand Embassy, making a particular study of shipbuilding.^[1]
• July 25 – English engineer Thomas Savery obtains a patent for "A new invention for raising of water... by the impellent force of fire", a steam pump.^[2]
• November 14 – First Eddystone Lighthouse illuminated,^[3] the first rock lighthouse in Europe.^[4]
• The piano is invented by Italian Bartolomeo Cristofori, originally named the "piano et forte" (meaning "soft and loud").
• A metronome is developed as a machine to measure musical tempo.

• November – Tani Jinzan, astronomer and calendar scholar, observes a fire destroy Tosa in Japan at the same time as a Leonid meteor shower, taking it as evidence to reinforce belief in the "Theory of Areas".

• February – Colin Maclaurin, Scottish mathematician (died 1746)
• February 16 – Pierre Bouguer, French mathematician (died 1758)
• March 26 – Václav Prokop Diviš, Czech theologian and natural scientist (died 1765)
• May 8 – Henry Baker, English naturalist (died 1774)
• July 17 – Pierre Louis Moreau de Maupertuis, French mathematician (died 1759)
• November 28 – Charlotta Frölich, Swedish agronomist (died 1770)

• August 18 – Nicolas Venette, French physician, sexologist and writer (born 1633)^[5]
• November 4 – Rasmus Bartholin, Danish scientist (born 1625)