Horrible Harry Books in Order
18 books by Suzy Kline. Reading level: Grades 2.9–3.9. Lower Grades (Ages 5–8).
Series books grow with readers — but that's also the trap. Most series start at one reading level and one content intensity and drift upward over the course of the run. Horrible Harry (18 books by Suzy Kline) lands at reading level Grades 2.9–3.9, with average content intensity 1.1/5. Intensity stays consistent across the series — a kid who can handle the first book can generally handle the rest.
The reading-order table below lists every book with per-volume reading level and intensity badges so you can spot any escalation before it catches your reader off guard. For a deeper dive into how we score text difficulty vs. emotional weight separately — and why series readers especially benefit from that split — see our methodology page.
Content Intensity Across the Series
ConsistentContent stays at a steady intensity level throughout the series.
Horrible Harry Reading Order
| # | Title | Reading Level | Content |
|---|---|---|---|
| 1 | Horrible Harry and the ant invasion Suzy Kline | Level 3-4 | Gentle |
| 2 | Horrible Harry and the battle of the bugs Suzy Kline | Level 3-4 | Gentle |
| 3 | Horrible Harry and the birthday girl Suzy Kline | Level 3-4 | Gentle |
| 4 | Horrible Harry and the Christmas surprise Suzy Kline | Level 2-3 | Gentle |
| 5 | Horrible Harry and the dragon war Suzy Kline | Level 3-4 | Gentle |
| 6 | Horrible Harry and the dungeon Suzy Kline | Level 3-4 | Gentle |
| 7 | Horrible Harry and The Goog Suzy Kline | Level 3 | Gentle |
| 8 | Horrible Harry and the hallway bully Suzy Kline | Level 3-4 | Mild |
| 9 | Horrible Harry and the June box Suzy Kline | Level 3-4 | Gentle |
| 10 | Horrible Harry and the locked closet Suzy Kline | Level 3-4 | Gentle |
| 11 | Horrible Harry and the Mud Gremlins Suzy Kline | Level 3-4 | Gentle |
| 12 | Horrible Harry and the scarlet scissors Suzy Kline | Level 3-4 | Gentle |
| 13 | Horrible Harry and the secret treasure Suzy Kline | Level 3-4 | Gentle |
| 14 | Horrible Harry and the stolen cookie Suzy Kline | Level 3-4 | Mild |
| 15 | Horrible Harry at Halloween Suzy Kline | Level 3-4 | Gentle |
| 16 | Horrible Harry goes cuckoo Suzy Kline | Level 3-4 | Gentle |
| 17 | Horrible Harry goes to sea! Suzy Kline | Level 3-4 | Gentle |
| 18 | Horrible Harry in room 2B Suzy Kline | Level 3-4 | Gentle |
All Horrible Harry Books
Horrible Harry and the ant invasion
Suzy Kline
Horrible Harry and the ant invasion
Suzy Kline
Horrible Harry and the battle of the bugs
Suzy Kline
Horrible Harry and the battle of the bugs
Suzy Kline
Horrible Harry and the birthday girl
Suzy Kline
Horrible Harry and the birthday girl
Suzy Kline
Horrible Harry and the Christmas surprise
Suzy Kline
Horrible Harry and the Christmas surprise
Suzy Kline
Horrible Harry and the dragon war
Suzy Kline
Horrible Harry and the dragon war
Suzy Kline
Horrible Harry and the dungeon
Suzy Kline
Horrible Harry and the dungeon
Suzy Kline
Horrible Harry and The Goog
Suzy Kline
Horrible Harry and The Goog
Suzy Kline
Horrible Harry and the hallway bully
Suzy Kline
Horrible Harry and the hallway bully
Suzy Kline
Horrible Harry and the June box
Suzy Kline
Horrible Harry and the June box
Suzy Kline
Horrible Harry and the locked closet
Suzy Kline
Horrible Harry and the locked closet
Suzy Kline
Horrible Harry and the Mud Gremlins
Suzy Kline
Horrible Harry and the Mud Gremlins
Suzy Kline
Horrible Harry and the scarlet scissors
Suzy Kline
Horrible Harry and the scarlet scissors
Suzy Kline
Horrible Harry and the secret treasure
Suzy Kline
Horrible Harry and the secret treasure
Suzy Kline
Horrible Harry and the stolen cookie
Suzy Kline
Horrible Harry and the stolen cookie
Suzy Kline
Horrible Harry at Halloween
Suzy Kline
Horrible Harry at Halloween
Suzy Kline
Horrible Harry goes cuckoo
Suzy Kline
Horrible Harry goes cuckoo
Suzy Kline
Horrible Harry goes to sea!
Suzy Kline
Horrible Harry goes to sea!
Suzy Kline
Horrible Harry in room 2B
Suzy Kline
Horrible Harry in room 2B
Suzy Kline
Questions about the Horrible Harry series
- What reading level is the Horrible Harry series?
- The Horrible Harry series by Suzy Kline is at a Grades 2.9–3.9 reading level (average Grade 3.4). Intended for Lower Grades (Ages 5–8). There are 18 books in the series.
- What order should I read the Horrible Harry books?
- The reading-order table above lists all 18 books with per-volume reading level and intensity ratings. Start with book 1 and read in publication order unless the table indicates a different recommended order for newer readers.
- What age is the Horrible Harry series appropriate for?
- The Horrible Harry series is recommended for Lower Grades (Ages 5–8). The average content intensity is 1.1/5. Check the intensity trajectory above to see whether content gets heavier across the series — if it does, sensitive readers may want to stop earlier in the run.