Who are the most important supporting characters?

Major Supporting Characters

1. Asher Glissen (artist) — A talented but underappreciated portraitist in Golden who forms a mentor‐like bond with Theo and whose art becomes central to Theo’s portrait bestowals.
2. Ellen (survivor/homeless woman) — An unhoused woman with a traumatic past; Theo befriends her, learns from her, and she becomes one of his deepest connections.
3. Tony (bookstore owner) — Gruff, war-scarred, and philosophical; he becomes Theo’s close friend and a frequent conversational partner.

Other Key Supporting Characters

4. Minnette Prentiss — Asher’s niece and Theo’s first portrait recipient who grows into self-awareness and authenticity.
5. Kendrick Whitaker — A university custodian who struggles with family trauma; Theo’s kindness towards him and his daughter deeply affects him.
6. Simone Lavoie — A somber, dedicated music student whose musical journey Theo supports.
7. James Ponder — Theo’s landlord and financial advisor of sorts; he helps facilitate Theo's mission and offers practical grounding.
8. Mrs. Anita Gidley — Mr. Ponder’s secretary; initially skeptical, later instrumental in coordinating Theo’s gifts.

Minor but Notable Characters

9. Lamisha Whitaker — Kendrick’s daughter (called “Scooby”); her injury and recovery become a significant focal point of Theo’s generosity.
10. Minnette’s family (Pearce Glissen, Gammy, Derrick) — Represent tensions between duty, art, and expectations in Minnette's life.
11. Katherine Lesker — A reporter trying to uncover Theo’s secretive portrait gifts; helps reveal and protect Theo’s identity.
12. Shep & Addie Carlile — Owners of The Chalice coffee shop; Shep displays Theo’s purchases, supporting both art and community.
13. Basil Cannonfield — A street performer whose artistry is overlooked until Theo notices him.

---

If you want, I can also sketch a map showing how these characters connect to each other and to Theo.

Sources: Supersummary, BookCompanion, reviews & character guides of Theo of Golden.