Is it musical theatre or theater?
Theatre and theater are different spellings of the same noun. Its spelling depends on the type of English you use.
- In British English, “theatre” is standard.
- In American English, “theater” is correct.
This is also true for similar words, such as center or centre, meter or metre, liter or litre, saber or sabre, and fiber or fibre.
It’s important to choose one type of English and use it consistently. The QuillBot Grammar Checker can help you with this.