Trevor Sandbourne is a 13 year old boy who goes to Stoneybrook Middle School (SMS) with The Baby Sitters Club members. He is in eighth grade, too, and went out briefly with Claudia Kishi, but it didn't get very far.
He is friends with Alan Gray, and was involved in Alan's scheme in Book #2 Claudia And The Phantom Phone Calls.
Trevor is a poet and is often off in his own little world, daydreaming or looking for inspiration for poems.
He writes for The Literary Voice collumn in the SMS school newspaper.
Trevor seems shy and quiet and Claudia found him to be too much focused on his poetry writing, rather than Claudia herself.