look down (one's) nose at (someone)

Translations
смотреть свысока на (кого-то)
She tends to look down her nose at people from different backgrounds.
Она склонна смотреть свысока на людей из других слоев общества.
Definitions
To regard someone with a sense of superiority or disdain; to treat someone as if they are less important, less intelligent, or less worthy.