“The largest known star in the universe is UY Scuti, a hypergiant with a radius around 1,700 times larger than the sun. And it’s not alone in dwarfing Earth’s dominant star”
Source: https://the-biggest.net/animals/what-is-the-largest-known-star.html
Betelgeuse, Deneb, and a few others all seem to get the distinction of being the most massive. In comparison our star is a shrimp. Some theories suggest that Betelgeuse went supernova a long time ago.