Possibly from Irish 'odhar' meaning pale or green, or a variant of the Gaelic name Odhran.
Orrin is most likely a variant spelling of Oren, a Hebrew name meaning "pine tree" (oren, אֹרֶן), the tall, aromatic evergreen prized in ancient Israel for its timber and its symbolic association with uprightness and longevity. Some scholars also connect the name to a Celtic root meaning "pale" or "white-skinned," which would give it a separate lineage entirely, though in practice the two traditions have blended in American usage without most bearers being aware of the distinction. In the Hebrew scriptures, Oren appears as a minor figure in the genealogies of the tribe of Judah (1 Chronicles 2:25), lending the name quiet biblical credentials without the weight of a major patriarch.
In American political history, the spelling Orrin is most prominently associated with Orrin Hatch, the longtime Utah senator (1977–2019) who also had an unlikely second career as a prolific songwriter of Christian and patriotic hymns — a detail that captures the name's dual quality of sober civic gravity and genuine personal warmth. Orrin (and Oren) enjoyed modest use through the nineteenth and early twentieth centuries before fading from the mainstream. Today it occupies an appealing niche for parents drawn to nature-rooted names with Old Testament texture.
Its two syllables feel balanced and complete, and the double-r spelling gives it a slight visual sturdiness that distinguishes it from lookalike names. As botanical names for boys gain renewed interest, Orrin is well positioned for quiet rediscovery.