Readonly models in Django admin interface?

The admin is for editing, not just viewing (you won't find a "view" permission). In order to achieve what you want you'll have to forbid adding, deleting, and make all fields readonly:

class MyAdmin(ModelAdmin):

    def has_add_permission(self, request, obj=None):
        return False

    def has_delete_permission(self, request, obj=None):
        return False

(if you forbid changing you won't even get to see the objects)

For some untested code that tries to automate setting all fields read-only see my answer to Whole model as read-only

EDIT: also untested but just had a look at my LogEntryAdmin and it has

readonly_fields = MyModel._meta.get_all_field_names()

Don't know if that will work in all cases.

EDIT: QuerySet.delete() may still bulk delete objects. To get around this, provide your own "objects" manager and corresponding QuerySet subclass which doesn't delete - see Overriding QuerySet.delete() in Django

Here are two classes I am using to make a model and/or it's inlines read only.

For model admin:

from django.contrib import admin

class ReadOnlyAdmin(admin.ModelAdmin):
    readonly_fields = []

    def get_readonly_fields(self, request, obj=None):
        return list(self.readonly_fields) + \
               [field.name for field in obj._meta.fields] + \
               [field.name for field in obj._meta.many_to_many]


    def has_add_permission(self, request):
        return False

    def has_delete_permission(self, request, obj=None):
        return False

class MyModelAdmin(ReadOnlyAdmin):
    pass

For inlines:

class ReadOnlyTabularInline(admin.TabularInline):
    extra = 0
    can_delete = False
    editable_fields = []
    readonly_fields = []
    exclude = []

    def get_readonly_fields(self, request, obj=None):
        return list(self.readonly_fields) + \
               [field.name for field in self.model._meta.fields
                if field.name not in self.editable_fields and
                   field.name not in self.exclude]

    def has_add_permission(self, request):
        return False


class MyInline(ReadOnlyTabularInline):
    pass