Publications of the Astronomical Society of the Pacific 107: 617-631, 1995 July A Catalog of the Youngest YSOs and Candidate Protostars MARCO D. POLLANEN AND P. A. FELDMAN Herzberg Institute of Astrophysics, National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada Electronic mail: marco@seurat.hia.nrc.ca, paf@hiaras.hia.nrc.ca ABSTRACT. We have compiled a catalog of candidate protostars from the major astronomical journals up to the end of 1993. The Belchman- Ichikawa color criterion was used as the main test of an author's claim that a source should be deemed a candidate protostar. Names, positions (1950 and 2000), LSR velocities, information on whether there are associated outflows, and references are provided. This catalog is meant to update an earlier compilation by Wynn-Williams (1982).