Karl Gunnar Malmquist (21 February 1893 – 27 June 1982) was a Swedish astronomer.
Gunnar Malmquist was born in Ystad, where he completed his secondary school education before matriculating at the Lund University in 1911.
His work in that field led, among other things, to his observation of the Malmquist bias.
As professor at the Uppsala Astronomical Observatory he got interested in Schmidt telescopes and took the initiative, together with Åke Wallenquist, to get a large Schmidt telescope installed at Uppsala University's Kvistabergs Observatorium (Kvistaberg Observatory, 1964), at the time one of the largest Schmidt telescopes in the world with a mirror of 135 cm and a corrector plate of 100 cm.
He also arranged for the university to construct a Schmidt telescope and build a dome at Mount Stromlo in Australia in 1956, "The Uppsala Southern Station".