Hume Cronyn Memorial Observatory, Scientific observatory at Western University in London, Canada.

The Hume Cronyn Memorial Observatory is a scientific research facility at Western University equipped with three main telescopes, including a 254 mm refractor and a 203 mm Schmidt camera. These instruments allow visitors and researchers to observe the sky and conduct astronomical studies.

Hume Blake Cronyn, a London lawyer, businessman and federal MP, died in 1933; his widow Frances Amelia Cronyn, granddaughter of brewer John Kinder Labatt, proposed a memorial to Western. Professor Harold Kingston suggested an observatory, and she funded the $40,000 building, opened on 25 October 1940. In 1958 William H. Wehlau added a 300 mm Cassegrain reflector for photometry.

The observatory's basement holds a 1940 period room and a science demonstration room, created for its 75th anniversary in 2015, plus a 1967 Elginfield Observatory room and a William Colgrove historic workshop. All are open to the public during public events. A Ginkgo tree given with the heliochronometer by the Arts Class of 1925 turns yellow in early November.

Public events are held in the evening, when the 1996 classroom on the main floor seats about 70 people. The basement history rooms, including a 1940 period room and a science demonstration room, are open to the public during these events. The building stands on the Western campus in London, Ontario.

The Gibbs Heliochronometer outside was made by Pilkington-Gibbs around 1906, one of about 1,000 produced; this one is stamped No. 953. A cam corrects for the equation of time, converting local solar time to mean solar time to within about a minute. The Arts Class of 1925 gave it with a Ginkgo tree, and it was moved in front of the observatory in 1952.