Helen Battles Sawyer Hogg, CC (1 August 1905 – 28 January 1993) was an astronomer noted for her research into globular clusters. She is best remembered for her astronomy column, which ran from 1951 until 1981 in the Toronto Star, and her articles on the history of astronomy which ran from 1946 until 1965 in the Journal of the Royal Astronomical Society of Canada under the title “Out of Old Books”.

A 1926 graduate of Mount Holyoke College, she went on to Harvard Observatory to work with Annie Jump Cannon and Harlow Shapley on star clusters. She received her doctorate in 1931 from Radcliffe College.

She married husband Frank Scott Hogg in 1930, and the two moved to Victoria, British Columbia. There Frank had a job at the Dominion Astrophysical Observatory. Helen was not hired, though, and had to work as his volunteer assistant. In 1935, the couple moved again to Ontario where she took a job at the David Dunlap Observatory. Helen Hogg's research during this time period focused on stars whose spectra contain absorption lines of elements including carbon, nitrogen and oxygen. Frank Hogg was director of the observatory from 1946 until his death in 1951.

Over the next six decades, she published numerous papers and established herself as a leader in the field of astronomy. In 1985, she married F. E. L. Priestley (Francis Ethelbert Louis Priestley) (1905–1988), a professor emeritus of English at the University of Toronto, who died in 1988. She died of a heart attack in 1993.

She won the Annie J. Cannon Award in Astronomy in 1949 and the Klumpke-Roberts Award in 1983.

• In 1967 she was awarded the prestigious Rittenhouse Astronomical Society Silver Medal Award for her outstanding achievements in astronomy. The Rittenhouse Astronomical Society was founded in honour of scholar and astronomer David Rittenhouse.
• In 1968 she was made an Officer of the Order of Canada and was promoted to Companion in 1976.