1610s, originally in the philosophical sense of "considered in relation to its object" (opposite of subjective), formed on pattern of Medieval Latin objectivus, from objectum "object" (see object (n.)) + -ive. Meaning "impersonal, unbiased" is first found 1855, influenced by German objektiv. Related: Objectively.
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.
<a href="https://www.etymonline.com/word/objectivism">Etymology of objectivism by etymonline</a>
Harper, D. (n.d.). Etymology of objectivism. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/objectivism