What degree in college do you get as are officially a mathematician?

There isn't one specific degree that officially makes you a "mathematician." The title is more about your profession and accomplishments than a specific degree. However, the most common path is to obtain a Doctor of Philosophy (Ph.D.) in Mathematics.

While a Bachelor's or Master's degree in mathematics can provide a foundation, a Ph.D. is generally required for research positions in academia and many advanced roles in industry that are considered "mathematician" positions. A Ph.D. involves significant original research and is the standard for contributing to the field at a high level.