Set favicon in django admin

To avoid duplicating anything of the original file, you can actually override the template while extending it (docs). So create your own template/admin/base_site.html:

{% extends "admin/base_site.html" %}
{% load static %}
{% block extrahead %}
    <link rel="shortcut icon" href="{% static 'yourapp/img/favicon.ico' %}" />
{% endblock %}