The Maunder Minimum, also known as the "prolonged sunspot minimum", is the name used for the period starting in about 1645 and continuing to about 1715 when sunspots became exceedingly rare, as noted by solar observers of the time.

The term was introduced after John A. Eddy published a landmark 1976 paper in Science. Astronomers before Eddy had also named the period after the solar astronomers Annie Russell Maunder (1868–1947) and E. Walter Maunder (1851–1928), who studied how sunspot latitudes changed with time. The period the husband and wife team examined included the second half of the 17th century. Two papers were published in Edward Maunder's name in 1890 and 1894, and he cited earlier papers written by Gustav Spörer. Since Annie was not granted a university degree (due to restrictions at the time), her contribution was not publicly recognized.