Yes, the largest known black hole is significantly larger than the largest known star. The largest stars, known as supergiants, can have radii on the order of hundreds to a few thousand times that of our Sun. For example, the red supergiant Betelgeuse has a radius estimated to be about 900 times that of the Sun.
In contrast, the largest known black holes, called supermassive black holes, can have masses ranging from millions to billions or even tens of billions of times that of the Sun. These black holes are located at the centers of galaxies and can have sizes on the scale of thousands to billions of kilometers.
For instance, the black hole at the center of the galaxy Messier 87 (M87), which was imaged by the Event Horizon Telescope in 2019, has a mass estimated to be about 6.5 billion times that of the Sun. Its event horizon, the boundary beyond which nothing can escape, is thought to be around 23 billion kilometers (about 14 billion miles) in diameter.
So, in terms of mass and size, supermassive black holes are significantly larger than even the most massive stars we know of.