noun
classicist
Refers to a person who follows or advocates classical principles, especially in art, literature, or music.
彼は古典主義者で、現代美術にはあまり興味がない。
He is a classicist and has little interest in modern art.
古典主義 is the abstract concept of classicism, while 古典主義者 refers to a person who adheres to it.
Compound of 古典 (classics) + 主義 (doctrine, -ism) + 者 (person).