  We compute bounds on the GUP parameters for two versions of GUP using
gravitational wave data from the events GW150914 and GW190521. The speed of the
graviton and photon are calculated in a curved spacetime modified by GUP,
assuming that these particles have a small mass. The observational bound on the
difference in their speeds translates to bounds on the GUP parameters. These
bounds are some of the best obtained so far in the context of quantum gravity
phenomenology.
