Justine Medina is an American labor organizer who worked as a packer at Amazon's JFK8 warehouse and served on the organizing committee of the Amazon Labor Union during its founding campaign. She was among the union's "salts" — organizers who took warehouse jobs specifically to build support for unionization — and was a visible presence at the union's landmark April 2022 election victory, later speaking publicly about the campaign alongside fellow organizer Karen Ponce.