- “In the name of the Mejiro family, I will fulfill this dream.”
- ―Mejiro McQueen
Mejiro McQueen (メジロマックイーン, Mejiro Makkuīn)  is a supporting character in Uma Musume: Pretty Derby and the secondary main character of its second season.
As one of the Mejiro family's pedigrees, she has a strong sense of pride though she is quite gullible and easily convinced. She may initially seem as a blunt and cold person, but she actually cares about others and will offer help when needed.
She is a petite horse girl with bright lavender hair, she has brown tips on her ears and a teal ribbon on her right one. Her eyes are violet and they have white highlights in the center. She seems to consistently look worried.
- 世界は僕らの言いなりさ (Sekai Wa Bokura No Iinari Sa)
- Waiting for Tomorrow
- Umapyoi Densetsu
- She won the Emperor Award (天皇賞) like her mother and grandmother did before her.
- She secretly stays on a diet to maintain her body shape for her long distance races.
- Mejiro McQueen's name comes from Steve McQueen.