Winn-Dixie is a stray dog that becomes Opal's companion and catalyst for change. He is in poor condition when Opal finds him, but she cares for him deeply. Winn-Dixie's friendly nature helps Opal interact with the townspeople and bring about positive changes in her life.

The preacher is Opal's father, a dedicated church leader and single parent. He is grieving the loss of his wife but remains a supportive and loving father to Opal, teaching her the values of kindness and forgiveness.

Miss Franny Block is the librarian of Naomi who shares numerous fascinating stories from her past. She inspires Opal to connect with Amanda Wilkinson, another young reader in the town.

Otis manages Gertrude’s Pets and is a shy character with a mysterious past that includes a stint in jail. He plays music for the animals, and his talents ultimately help him bond with the people of Naomi and coax Winn-Dixie out of hiding.

Amanda Wilkinson is around Opal's age and initially comes across as snotty. She is dealing with her own grief, and over time, she and Opal become more understanding and kinder towards each other.

Gloria Dump is an older woman with a beautiful garden who befriends Opal. She is blind, and Opal visits her to share stories. Gloria teaches Opal valuable lessons about seeing with one's heart and understanding life's complexities.

Dunlap and Stevie Dewberry are brothers around Opal's age. Initially, Stevie is mean to Opal, but Dunlap is more open to friendship. Over time, they become friends with Opal, showing their kinder sides.

Littmus Block is Miss Franny Block’s great-grandfather and the creator of the Littmus Lozenge. Although deceased during the story, his legacy lives on, contributing to the themes of loss and resilience.