Green’s Dictionary of Slang

(Aus./N.Z.) the Society of St Vincent de Paul.

1995		Tablet (Dunedin) 8 Jan. 6: Over 20 per cent of the St Vincent de Paul Society belong to the youth section or young ‘Vinnies’ [...] The ‘Vinnies’ visit people in hospitals, assist in soup kitchens, and with clothing and food drives for the society’s shops and foodbanks [DNZE].
2002		St Vincent De Paul Society (Aus.) 🌐 [heading] Vinnies Donation and Recycle Division.
2005		L. Redhead Rubdown [ebook] [I] grabbed a shapeless Vinnies jumper and a pair of big round glasses.