Best Thriller Books for 9 Year Olds (2026): 4 Compared

Nine-year-olds love a good mystery, and the best thriller books for 9 year olds keep the suspense age-appropriate. We compared four middle-grade thrillers by fit, contents and edition, value, and the listed reading age, using only what each listing publishes.

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The picks

#	Product	Shelf Score	Buy
1	The Sherlock Society	9.7/10	Buy on Amazon
2	The Westing Game	9.7/10	Buy on Amazon
3	Another	9.6/10	Buy on Amazon
4	Hideout	9.5/10	Buy on Amazon

1

The Sherlock Society

James Ponti·9.7/10 Shelf Score

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The Shelf Score runs from 9.2 to 9.8 and weighs fit for the reader or goal (35 points), contents and edition (25), value (25) and listed reading age or level (10, where the listing gives one), using only what the book listing states. How we pick ›

A 368-page mystery for ages 9 to 11; skip it if the reader wants horror.

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Pros

• Reading age 9 to 11, the exact target
• 368 pages from Aladdin
• Published September 30, 2025

Cons

• Reading age is marked as from customers
• 368 pages may be long for new readers
• A mystery, not horror

2

The Westing Game

Ellen Raskin·9.7/10 Shelf Score

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The Shelf Score runs from 9.2 to 9.8 and weighs fit for the reader or goal (35 points), contents and edition (25), value (25) and listed reading age or level (10, where the listing gives one), using only what the book listing states. How we pick ›

A 192-page classic mystery for ages 10 and up; skip it for newer 2025 books.

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Pros

• A classic mystery
• 192 pages from Puffin Books
• Published September 28, 2021

Cons

• Reading age is marked as from customers
• Aimed at 10+, above the target
• 2021, older than the 2025 picks

3

Another

Paul Tremblay·9.6/10 Shelf Score

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The Shelf Score runs from 9.2 to 9.8 and weighs fit for the reader or goal (35 points), contents and edition (25), value (25) and listed reading age or level (10, where the listing gives one), using only what the book listing states. How we pick ›

A 256-page horror novel for ages 8 to 12; skip it for gentle mysteries.

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Pros

• A middle-grade horror novel from 2025
• 256 pages, published July 22, 2025
• Reading age 8 to 12 covers the target

Cons

• Reading age is not marked as from customers
• Horror, not a mystery
• 256 pages may be intense for some 9-year-olds

4

Hideout

Watt Key·9.5/10 Shelf Score

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The Shelf Score runs from 9.2 to 9.8 and weighs fit for the reader or goal (35 points), contents and edition (25), value (25) and listed reading age or level (10, where the listing gives one), using only what the book listing states. How we pick ›

A 336-page survival thriller for ages 10 to 13; skip it for younger 9-year-olds.

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Pros

• 336 pages of survival thriller
• Reading age 10 to 13 is stated
• From Square Fish

Cons

• Reading age is not marked as from customers
• Aimed above age 9
• 2018, the oldest here

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More picks to compare

• Lost at the School Field TripFor ages 9 to 16: 206 pages, 2025.Check on Amazon

Compare the picks

Book details as published on each listing, collected 20 October 2026.

How we scored them

The Shelf Score weighs fit for the reader, contents and edition, value, and the listed reading age where one is given. Every pick here lists a reading age, two marked as from customers. How we pick explains the weights.

Scores run from 9.2 to 9.8: each book’s point total is placed on that range, so more points always means a higher score. Reading age or level counts on a list where at least one listing gives one, and a book whose listing gives none then scores zero on it. Where no listing gives one, the score is taken over the other 85 points. Books carry no warranty, so warranty is not scored.

How to choose the best thriller books for 9 year olds

Match the reading age

The Sherlock Society lists 9 to 11 years, the exact target. Another lists 8 to 12, while The Westing Game lists 10+ and Hideout lists 10 to 13. Two of the four are marked as from customers. For a 9-year-old, the 9 to 11 and 8 to 12 picks are the closest fit.

Mystery or horror

Two are mysteries: The Sherlock Society and The Westing Game. One is horror: Another, a middle-grade horror novel from Paul Tremblay. Hideout is a survival thriller. Know whether the reader wants clues, scares or survival before you choose. Older readers have their own list at best thriller books for 13 year olds.

Length and edition

Pages run from 192 to 368. The two 2025 books are the newest editions, while Hideout is from 2018. Check the publisher and date on the listing to pick the right edition. More age-matched lists are on our best history books for 9 year olds.

Before you buy

• Check the listed reading age against the child; two of the four are marked as from customers.
• Decide between mystery, horror and survival before you shop.
• Note the publication date and publisher on the listing to pick the right edition.

Frequently Asked Questions

Which thriller is best for a 9-year-old?

The Sherlock Society lists a reading age of 9 to 11 years, with 368 pages from 2025.

Is there a horror option?

Yes: Another by Paul Tremblay, a 256-page middle-grade horror novel for ages 8 to 12, from 2025.

Which are the longest books here?

The Sherlock Society at 368 pages and Hideout at 336 pages.

Still deciding? Our top pickThe Sherlock Society

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Related lists

See every middle grade list and all kids and teens lists. Also see our best thriller books for 13 year olds. Also see our best history books for 9 year olds.

More lists: funny books for 11 year olds, fact books for 11 year olds and star wars books for 9 year olds.