  We present the Sydney Radio Star Catalogue, a new catalogue of stars detected
at megahertz to gigahertz radio frequencies. It consists of 839 unique stars
with 3,405 radio detections, more than doubling the previously known number of
radio stars. We have included stars from large area searches for radio stars
found using circular polarisation searches, cross-matching, variability
searches, and proper motion searches as well as presenting hundreds of newly
detected stars from our search of Australian SKA Pathfinder observations. The
focus of this first version of the catalogue is on objects detected in surveys
using SKA precursor instruments; however we will expand this scope in future
versions. The 839 objects in the Sydney Radio Star Catalogue are distributed
across the whole sky and range from ultracool dwarfs to Wolf-Rayet stars. We
find that the radio luminosities of cool dwarfs are lower than the radio
luminosities of more evolved sub-giant and giant stars. We use X-ray detections
of 530 radio stars by the eROSITA soft X-ray instrument onboard the SRG
spacecraft to show that almost all of the radio stars in the catalogue are
over-luminous in the radio, indicating that the majority of stars at these
radio frequencies are coherent radio emitters. The Sydney Radio Star Catalogue
can be found in Vizier or at https://radiostars.org.
