What is the term for a person with same first and last name?
They are very likely informally termed tautonyms or as the Wikipedia page tells me, linguistically called reduplicants. There's a page full of people with reduplicated names including:
- José José
- Justo Justo
- Kelly Kelly
- Lisa Lisa
- Thomas T. Thomas
The term is not used solely for names with reduplicated first and last names, but also for other variants such as Jar Jar Binks or Richie Rich.