Yes, doing Kegel exercises, which is also sometimes called "pelvic floor muscle training," can help control the symptoms of overactive bladder. This tends to work best if the Kegels are combined with an overall program of bladder training, which helps a person learn to better cope with the sudden urges to pee that are characteristic of overactive bladders.
Most people need to invest at least a few weeks practicing Kegels and bladder training exercises however, so don't be discouraged if you don't notice improvement right away. Many research studies have proven that a 6-to-8 week program of exercises can be very effective in reducing incontinence, especially if coaching from a good physical therapist is involved.
Of course, if you're concerned about overactive bladder symptoms, always be sure to start by discussing the issue with your doctor, especially if the problem is new or has suddenly gotten worse. Before starting Kegels or bladder training, you'll want to make sure that the overactive bladder isn't being caused by another medical issue such as diabetes, infection, a medication side effect, or a neurological disease.