Just for reference, in the States, third graders are generally about eight years old. If you’re fortunate, you may already have a big reader on your hands who isn’t afraid to shoot for younger middle-grade titles like some of those on this list. Typically, though most eight-year-olds prefer smaller chapter books, under 150 pages, with lots of pictures and larger fonts than the typical middle-grade book. Kids at this age also like series — they want to remain in the same universe for as long as possible, so most of the books on this list are part of series.
These chapter books for third graders are good for independent reading and also for readalouds! All except one are heavily illustrated, and I’ve tried to include picks for a variety of interests.