Scott Innes provided the voice of Scooby for many years. He also provided the voice for Shaggy for a time and the voice of Scrappy Doo. Innes took over the role after Don Messick who was the original voice of both Scooby and Scrappy died in 1997.
Scott Innes is not just an actor and the voice of Scooby Doo, he is a huge Scooby Doo fan. If you have seen the tour of Innes' home in the extras included as part of Scooby Doo Seasons 1 and 2 dvd, then you will understand his passion for the lovable canine and the series.
Like many of the voice actors, Innes has also provided the voices of other cartoon characters, but by far, Scooby and Shaggy are the most well known.
If you want to find out more about Scott Innes and his current projects, check out his website.