[Answered ]-Hyperlink to not editable foreign key filed in django admin

this work for me:

define a method in your models.py like this:

class Campus(TimeStampedModel, StatusModel):
    # other fields

    gallery = models.ForeignKey(Album, editable=False, related_name='campus')

    def gallery_link(self):
        return '<a href="%s">%s</a>' % ('/test/url', 'Test name')

    gallery_link.short_description = "Gallery Link"
    gallery_link.allow_tags = True

And use list_display in admin.py:

class CampusAdmin(admin.ModelAdmin):
    list_display = ('gallery_link',)

admin.site.register(Campus, CampusAdmin)

if you want to work with your solution you must:

1-change def gallery to another name.

2-add new name to list_display.

class CampusAdmin(admin.ModelAdmin):
    list_display = ('gallery_link',)
    readonly_fields = ('gallery_link',)

    def gallery_link(self, instance):
        return '<a href="%s">%s</a>' % ('/test/url', 'Test name')

    gallery_link.short_description = "Gallery"
    gallery_link.allow_tags = True

admin.site.register(Campus, CampusAdmin)