early 14c., from Old French final "final, last," and directly from Late Latin finalis "of or pertaining to an end, concluding, final," from finis "end" (see finish (v.)). As a noun, late 14c., "that which comes last;" meaning "final contest" in a sporting sense is from 1880. As a shortening of final examination, from 1880.
word-forming element meaning "one who does or makes," also used to indicate adherence to a certain doctrine or custom, from French -iste and directly from Latin -ista (source also of Spanish, Portuguese, Italian -ista), from Greek agent-noun ending -istes, which is from -is-, ending of the stem of verbs in -izein, + agential suffix -tes.
Variant -ister (as in chorister, barrister) is from Old French -istre, on false analogy of ministre. Variant -ista is from Spanish, popularized in American English 1970s by names of Latin-American revolutionary movements.
<a href="https://www.etymonline.com/word/finalist">Etymology of finalist by etymonline</a>
Harper, D. (n.d.). Etymology of finalist. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/finalist