Guy Thomas Mackie (born 1955) is an amateur astronomer in British Columbia, Canada, who was instrumental in merging the Vernon Astronomy Group and the Okanagan Astronomical Society into the RASC Okanagan Centre, and then served three years as President of Okanagan Centre. Mackie also started Okanagan
Centre's telescope rental program, became Director of the club observatory in 2009, worked on the
organizing committee of the Mount Kobau Star Party, and served as moderator of the AstroOkanagan email group. On one of his nocturnal sojourns in 2001, Guy noticed a small cluster of 29 stars that had gone previously unnoticed, and the United States Naval Observatory confirmed this discovery a few weeks later. In 2003 the cluster was catalogued and published as Mackie 1.

Mackie served as the registrar at the 2005 RASC General Assembly and won the RASC Service Award in 2010.