- Seasons of the Cat
- Seasons of the Dog
- Seasons of the Moon Series, Books 1-4: Six Moon Summer, All Hallows' Moon, Long Night Moon, and Gray...
- Seasons Within
- Seaward Born
- Seb's Train
- Sebastian and the Hidden Book
- Sebastian Shy and the Shadow Puppet Monster Friend
- Sebastian's adventure on his way to school
- Sebastián
- Sebastián y su aventura camino a la escuela
- Seclusion Point
- Second Base
- Second Book of Tales
- Second Chance
- Second Chance Summer
- Second Chances
- Second Chances - A "Chosen" Short Story 2.5
- Second Daughter
- Second Daughter (The Royals of Dharia, Book Two)
- Second Face
- Second Family
- Second Fiddle
- Second Grade Stinks
- Second Helpings
- Second Impact
- Second Lives
- Second Sight (Sojourner Series Book 3)
- Second Sight (Sojourner Series Book 3)
- Second Skin
- Second Sleep
- Second Son
- Second Star
- Second String Center #10
- Second Term at L'Etoile
- Second Time's the Charm #7
- Second to None
- Seconde nature
- Secondhand Charm
- Seconds Away
- Seconds Away (Book Two)
- Seconds Before Sunrise
- Seconds Out
- Secret Academy - Gefährliche Liebe (Band 2)
- Secret Academy - Verborgene Gefühle (Band 1)
- Secret Admirer
- Secret Agent
- Secret Agent Josephine's ABCs
- Secret Agent Josephine's Numbers
- Secret Agent Robot Command
- Secret City
- Secret Clique (Replica #5)
- Secret Coders
- Secret Coders: Monsters & Modules
- Secret Coders: Paths & Portals
- Secret Coders: Potions & Parameters
- Secret Coders: Robots & Repeats
- Secret Coders: Secrets & Sequences
- Secret Game. Brichst du die Regeln, brech ich dein Herz (Romantic Suspense meets Dark Academia)
- Secret Garden
- Secret Genius
- Secret Holiday
- Secret Horse
- Secret Identity
- Secret Illusions (Salmon Run - Book 4)
- Secret in Grandma's Attic
- Secret in St. Something
- Secret Keeper
- Secret Letters From 0 To 10
- Secret Lies
- Secret Magics of Maine
- Secret of Betrayal
- Secret Of Bradbury Mansion
- Secret Of Devil Lake
- Secret of Omordion
- Secret of the Cave
- Secret of the Crystal Dragon
- Secret of the Dragon's Breath
- Secret of the Dragon's Eye
- Secret of the Lake: Book 1
- Secret of the Night Ponies
- Secret of the Red Arrow