The biggest known star is UV Scuti. It's 1700 times bigger than sun The star lies near the center of the Milky Way, roughly 9,500 light-years away from Earth. Located within the constellation Scutum, UY Scuti is a hypergiant star. Learn more stars is galaxies

The smallest known star is EBLM J0555-57Ab. It's about the size of Saturn—roughly 0.084 times the radius of our Sun—and just barely massive enough to sustain hydrogen fusion, which is what defines a star. It’s part of a binary system about 600 light-years away. If it were just a little less massive, it would be a brown dwarf (a "failed star"). Want a visual comparison between it and our Sun or Jupiter?