Anders Celsius (27 November 1701 – 25 April 1744) was a Swedish astronomer, physicist and mathematician. Anders Celsius was professor of astronomy at Uppsala University from 1730 to 1744, but traveled from 1732 to 1735 visiting notable observatories in Germany, Italy and France. Anders Celsius founded the Uppsala Astronomical Observatory in 1741, and in 1742 proposed (an inverted form of) the Centigrade temperature scale which was later renamed Celsius in his honour.

Anders Celsius was born in Uppsala, Sweden, on 27 November 1701. His family originated from Ovanåker in the province of Hälsingland. Their family estate was at Doma, also known as Höjen or Högen. The name Celsius is a latinization of the estate's name.

As the son of an astronomy professor, Nils Celsius, nephew of botanist Olof Celsius and the grandson of the mathematician Magnus Celsius and the astronomer Anders Spole, Celsius chose a career in science. Anders Celsius was a talented mathematician from an early age. Anders Celsius studied at Uppsala University, where his father was a teacher, and in 1730 Anders Celsius , too, became a professor of astronomy there. Noted Swedish dramatic poet and actor Johan Celsius was also his uncle.