What is another word for a rigid person?

Another word for a rigid person is inflexible person, stubborn person, obstinate person, uncompromising person, strict person, disciplinarian, stickler, perfectionist, or set in their ways person, depending on nuance. If rigid person enforces rules strictly, you might call them disciplinarian, authoritarian, or hardliner. If they insist on details, you might call them stickler, perfectionist, or nitpicker. If they refuse to change opinions, you might call them stubborn, obstinate, or hard-nosed. Colloquially, you might call rigid person uptight, stiff, or hardheaded. In psychology, rigid person might be described as having obsessive compulsive personality traits or being inflexible. So alternative terms include inflexible person, stubborn person, uncompromising person, strict person, disciplinarian, stickler, perfectionist, and uptight person, all describing someone who does not adapt easily, insists on own way, and adheres strictly to routines and rules.