1540s, "to call or mention by name" (common in 17c., but now rare or obsolete), a back-formation from nomination or else from Latin nominatus, past participle of nominare "to name, call by name, give a name to," also "name for office," from nomen "name" (from PIE root *no-men- "name"). Later "to appoint or designate by name to some office or duty" (1560s); "to propose or formally enter (someone's name) as a candidate for election" (c. 1600). It also occasionally was used from c. 1600 with a sense "give a name to." Related: Nominated; nominating.
word-forming element in legal English (and in imitation of it), representing the Anglo-French -é ending of past participles used as nouns (compare -y (3)). As these sometimes were coupled with agent nouns in -or, the two suffixes came to be used as a pair to denote the initiator and the recipient of an action.
Not to be confused with the French -ée that is a feminine noun ending (as in fiancée), which is from Latin -ata.
<a href="https://www.etymonline.com/word/nominee">Etymology of nominee by etymonline</a>
Harper, D. (n.d.). Etymology of nominee. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/nominee