According to BeardedDragonFood.com, bearded dragons can eat tomatoes. Tomatoes are full of vitamin A, which is good for bearded dragons. However, tomatoes should always be fed to bearded dragons as part of a diet and not as a sole source of nutrition.
Feeding bearded dragons too many tomatoes can make them sick. Generally, fruit of any kind should only make up around ten percent of a bearded dragon's diet. The best way to feed tomatoes to a bearded dragon is by placing a couple of slices on top of leafy greens such as collard greens or mustard greens. Always thoroughly wash tomatoes before feeding them to a bearded dragon.