My data looks like this: foo_list: [ { id: '98aa4987-d812-4aba-ac20-92d1079f87b2', name: 'Foo 1', slug: 'foo-1' }, { id: '98aa4987-d812-4aba-ac20-92d1079f87b2', name: 'Foo 1', slug: 'foo-1' } { id: '157569ec-abab-4bfb-b732-55e9c8f4a57d', name: 'Foo 3', slug: 'foo-3' } ] Where foo_list is a field in a model called Bar. Notice that the first and second objects in the array are complete duplicates. Aside from the obvious solution of switching to PostgresSQL, what MongoDB query can I run to remove duplicate entries from foo_list? Similar answers that do not quite cut it: http://stackoverflow.com/a/16907596/432 http://stackoverflow.com/a/18804460/432 These questions answer the question if the array had bare strings in it. However in my situation the array is filled with objects. I hope it is clear that I am not interested in a query; I want the duplicates to be gone from the database forever.