A few caveats: First, this is only known stars, there could be larger ones out there. Second, some of these stars are variable, meaning that they regularly expand and shrink. And lastly, there is, like virtually all astronomy measurements, an inherent bit of error. But it should be fairly close.

1.  VY Canis Majoris

This red hyper-giant star is by far the largest known. It has an estimated radius between 1800 and 2100 times the radius of our Sun. With this size it would reach nearly to the orbit of Saturn if placed in our solar system. The star is located roughly 4,900 light-years from Earth in the constellation Canis Majoris.