The Faint Sky Variability Survey Catalog of Galaxy Clusters and Rich Groups contains a a large sample of 598 galaxy clusters and rich groups discovered in the data of the Faint Sky Variability Survey (FSVS). The clusters have been identified using a fully automated, semi-parametric technique based on a maximum likelihood approach applied to Voronoi tessellation, and enhanced by color discrimination. The sample covers a wide range of richness, has a density of ~28 clusters per square degree, and spans a range of estimated redshifts of 0.05 < z < 0.9 with mean <z> = 0.345. Assuming the presence of a cluster red sequence, the uncertainty of the estimated cluster redshifts is assessed to be sigma ~ 0.03. Containing over 100 clusters with z > 0.6, the catalog contributes substantially to the current total of optically-selected, intermediate-redshift clusters, and complements the existing, usually X-ray selected, samples. The FSVS fields are accessible for observation throughout the whole year, making them particularly suited for large follow-up programs. The construction of this FSVS Cluster Catalogue completes a fundamental component of the authors' continuing program to investigate the environments of quasars and the chemical evolution of galaxies. The present table contains the list of all clusters with their basic parameters. This table was created by the HEASARC in July 2006 based on the table cluster_catalogue.txt copied from the first author's website <a href="https://web.archive.org/web/20100318044103/www-astro.physics.ox.ac.uk/~iks/FSVScatalogue/">https://web.archive.org/web/20100318044103/www-astro.physics.ox.ac.uk/~iks/FSVScatalogue/</a>; (no longer available, unfortunately). Refer instead to <a href="https://cdsarc.unistra.fr/viz-bin/cat/J/MNRAS/369/1334">https://cdsarc.unistra.fr/viz-bin/cat/J/MNRAS/369/1334</a>; for the data files and to <a href="https://www.noao.edu/survey-archives/fsvs/">https://www.noao.edu/survey-archives/fsvs/</a>; for additional information about the survey. This is a service provided by NASA HEASARC .