What is the name of the schoolmaster in Hard Times?

The schoolmaster in Hard Times is Thomas Gradgrind.

Thomas Gradgrind is introduced at the school in Coketown insisting that children be taught nothing but “Facts.” He represents Dickens's satire of rigid utilitarian education: a system that values statistics, definitions and practical calculation while dismissing imagination, emotion and experience. Gradgrind is both the school's superintendent and the father of Louisa and Tom.

His educational philosophy shapes his family as severely as it shapes his pupils. Louisa grows up unable to express her feelings, while Tom becomes resentful and morally reckless. By contrast, Sissy Jupe, the circus girl who struggles with Gradgrind's factual lessons, embodies kindness, loyalty and imagination.

A frequent mistake is choosing Josiah Bounderby, who is closely associated with Gradgrind. Bounderby is a wealthy mill owner and Gradgrind's business ally, not the schoolmaster. Stephen Blackpool is one of Bounderby's workers, and Mr. Slackbridge is a trade-union agitator. Gradgrind eventually recognises the damage caused by his narrow philosophy.