Helen Battles Sawyer Hogg (August 1, 1905 – January 28, 1993) was an American-Canadian astronomer who pioneered research into globular clusters and variable stars. She was the first female president of several astronomical organizations and a notable woman of science in a time when many universities would not award scientific degrees to women. Her scientific advocacy and journalism included astronomy columns in the Toronto Star ("With the Stars", 1951–81) and the Journal of the Royal Astronomical Society of Canada ("Out of Old Books", 1946–65). She was considered a "great scientist and a gracious person" over a career of sixty years.