diff --git a/ansible/inventory/group_vars/all/apt b/ansible/inventory/group_vars/all/apt
index 5285fba6c..394532cb0 100644
--- a/ansible/inventory/group_vars/all/apt
+++ b/ansible/inventory/group_vars/all/apt
@@ -27,6 +27,8 @@ apt_config: []
 apt_keys: []
 
 # A list of Apt repositories. Each item is a dict with the following keys:
+# * name: the <name>.sources filename part. Optional. Default is 'kayobe' and
+#   the default filename is 'kayobe.sources'.
 # * types: whitespace-separated list of repository types, e.g. deb or deb-src
 #   (optional, default is 'deb')
 # * url: URL of the repository
diff --git a/ansible/roles/apt/defaults/main.yml b/ansible/roles/apt/defaults/main.yml
index 5851d1908..6b53211e3 100644
--- a/ansible/roles/apt/defaults/main.yml
+++ b/ansible/roles/apt/defaults/main.yml
@@ -30,6 +30,8 @@ apt_keys_path: "/etc/apt/keyrings"
 apt_keys: []
 
 # A list of Apt repositories. Each item is a dict with the following keys:
+# * name: the <name>.sources filename part. Optional. Default is 'kayobe' and
+#   the default filename is 'kayobe.sources'.
 # * types: whitespace-separated list of repository types, e.g. deb or deb-src
 #   (optional, default is 'deb')
 # * url: URL of the repository
diff --git a/ansible/roles/apt/tasks/repos.yml b/ansible/roles/apt/tasks/repos.yml
index b63139e7f..9f8131ae5 100644
--- a/ansible/roles/apt/tasks/repos.yml
+++ b/ansible/roles/apt/tasks/repos.yml
@@ -13,11 +13,14 @@
 - name: Configure apt repositories
   template:
     src: "kayobe.sources.j2"
-    dest: "/etc/apt/sources.list.d/kayobe.sources"
+    dest: "/etc/apt/sources.list.d/{{ reponame }}.sources"
     owner: root
     group: root
     mode: 0644
   become: true
+  loop: "{{ apt_repositories }}"
+  vars:
+    reponame: "{{ item.name | default('kayobe') }}"
   notify:
     - Update apt cache
 
diff --git a/ansible/roles/apt/templates/kayobe.sources.j2 b/ansible/roles/apt/templates/kayobe.sources.j2
index b63f600de..bc99a19fe 100644
--- a/ansible/roles/apt/templates/kayobe.sources.j2
+++ b/ansible/roles/apt/templates/kayobe.sources.j2
@@ -1,12 +1,13 @@
 # {{ ansible_managed }}
 
 {% for repo in apt_repositories %}
+{% if reponame == repo.name | default('kayobe') %}
 Types: {{ repo.types | default('deb') }}
 URIs: {{ repo.url }}
 Suites: {{ repo.suites | default(ansible_facts.distribution_release) }}
 Components: {{ repo.components | default('main') }}
 {% if repo.signed_by is defined %}
-Signed-by: {{ apt_keys_path }}/{{ repo.signed_by }}
+Signed-by: {% if not repo.signed_by.startswith('/') %}{{ apt_keys_path }}/{% endif %}{{ repo.signed_by }}
 {% endif %}
 {% if repo.architecture is defined %}
 Architecture: {{ repo.architecture }}
@@ -15,4 +16,5 @@ Architecture: {{ repo.architecture }}
 Trusted: {{ repo.trusted | bool }}
 {% endif %}
 
+{% endif %}
 {% endfor %}
diff --git a/doc/source/configuration/reference/hosts.rst b/doc/source/configuration/reference/hosts.rst
index 87fddbccc..9e06722e3 100644
--- a/doc/source/configuration/reference/hosts.rst
+++ b/doc/source/configuration/reference/hosts.rst
@@ -366,6 +366,8 @@ Kayobe supports configuration of custom Apt repositories via the
 The format is a list, with each item mapping to a dict/map with the following
 items:
 
+* ``name``: the ``<name>.sources`` filename part. Optional. Default is
+  ``kayobe`` and the default filename is ``kayobe.sources``.
 * ``types``: whitespace-separated list of repository types, e.g. ``deb`` or
   ``deb-src`` (optional, default is ``deb``)
 * ``url``: URL of the repository
diff --git a/etc/kayobe/apt.yml b/etc/kayobe/apt.yml
index 9302675c3..4027d4365 100644
--- a/etc/kayobe/apt.yml
+++ b/etc/kayobe/apt.yml
@@ -27,6 +27,8 @@
 #apt_keys:
 
 # A list of Apt repositories. Each item is a dict with the following keys:
+# * name: the <name>.sources filename part. Optional. Default is 'kayobe' and
+#   the default filename is 'kayobe.sources'.
 # * types: whitespace-separated list of repository types, e.g. deb or deb-src
 #   (optional, default is 'deb')
 # * url: URL of the repository
diff --git a/releasenotes/notes/ubuntu-sources-configure-c2aff9915db76d07.yaml b/releasenotes/notes/ubuntu-sources-configure-c2aff9915db76d07.yaml
new file mode 100644
index 000000000..4c4c71503
--- /dev/null
+++ b/releasenotes/notes/ubuntu-sources-configure-c2aff9915db76d07.yaml
@@ -0,0 +1,11 @@
+---
+fixes:
+  - |
+    Adds a ``name`` field to elements of ``apt_repositories``, which specifies
+    the name of the repository file (without the ``.sources`` suffix). The
+    default value of this field is ``kayobe`` and it may be omitted. The user
+    can override the default by providing a different name, such as ``ubuntu``,
+    and new repository data. This way, the default file,
+    ``/etc/apt/source.list.d/ubuntu.sources``, will be overwritten by the
+    provided repository configuration.
+    `LP#2107280 <https://bugs.launchpad.net/kayobe/+bug/2107280>`__