There are a lot of fast superheroes out there. The Flash is probably the most well-known speedster in the DC Universe, but Wonder Woman isn't far behind. In fact, when it comes to raw speed, Wonder Woman might even be faster than The Flash.
The reason for this is because Wonder Woman's super-speed is derived from her superhuman strength. This means that she can accelerate and reach top speeds much quicker than The Flash can. In addition, Wonder Woman's top speeds are likely higher than The Flash's as well.
So, while The Flash might be able to outrun Wonder Woman over long distances, when it comes to a short race, Wonder Woman is probably the faster superhero.