This readalike is in response to a patron's book-match request. If you would like personalized reading recommendations, fill out the book-match form and a librarian will email suggested titles to you.
Ender's Game:
Andrew "Ender" Wiggins is the result of a desperate breeding experiment, combined with years of harsh & unforgiving training. Ender thinks he is only playing computer simulated wargames--in fact, he is commanding the last great fleet of Earth.
If you liked Ender's Game by Orson Scott Card, you may enjoy these other titles:

Archangel by Sharon Shinn
A dash of science fiction, a handful of fantasy, and a sprinkling of suspense enliven the story of the Archangel Gabriel and his reluctant wife Rachel.

The City of Ember (and series) by Jeanne DuPrau
In a post-apocalypse city on the verge of collapse, 12-year-olds Lina and Doon join forces to flee to an unknown world above ground.

D.A. by Connie Willis
Theodora Baumgarten has just been selected as an IASA space cadet, and therein lies the problem. She didn't apply for the ultra-coveted posting, and doesn't relish spending years aboard the ship to which she's been assigned. But the plucky young heroine, in true Heinlein fashion, has no plans to go along with the program. Aided by her hacker best friend Kimkim, in a screwball comedy that has become Connie Wills' hallmark, Theodora will stop at nothing to uncover the conspiracy that has her shanghaied.