This Catalogue is an update to Helen Sawyer Hogg's Third Catalogue on Variable Stars in Globular Clusters (1973, David Dunlap Observatory Publications, Volume 3, Number 6). This update is based mainly on reference cards prepared by Helen Sawyer Hogg from articles published in the literature in the period 1973 to 1988. There are also some references entered from more recent literature and we are attempting to bring the catalogue up to date. Not all known globular clusters have been included, as the literature search is not at this point complete.