Pet form or diminutive, possibly from names like Opal; informal and affectionate in character.
Oppie is likely a pet form or diminutive, perhaps from names like Opal, and it has the affectionate, informal quality that diminutives often carry. The name feels friendly, intimate, and a little old-fashioned in a charming way.
Its brevity gives it a nickname energy even when used as a full given name. As a stand-alone name, Oppie is light and playful. It has the soft edges of a household name that has been allowed into public use.
Because it is so short, its character comes mainly from tone rather than etymology. Oppie feels warm, unpretentious, and endearingly rare.