diff --git a/LibreNMS/Alert/Transport/Alertmanager.php b/LibreNMS/Alert/Transport/Alertmanager.php
index 8e06a35430..4d84e19ac0 100644
--- a/LibreNMS/Alert/Transport/Alertmanager.php
+++ b/LibreNMS/Alert/Transport/Alertmanager.php
@@ -36,10 +36,13 @@ class Alertmanager extends Transport
         $alertmanager_opts = $this->parseUserOptions($this->config['alertmanager-options']);
         $alertmanager_opts['url'] = $this->config['alertmanager-url'];
 
-        return $this->contactAlertmanager($obj, $alertmanager_opts);
+        $alertmanager_username = $this->config['alertmanager-username'];
+        $alertmanager_password = $this->config['alertmanager-password'];
+
+        return $this->contactAlertmanager($obj, $alertmanager_opts, $alertmanager_username, $alertmanager_password);
     }
 
-    public function contactAlertmanager($obj, $api)
+    public function contactAlertmanager($obj, $api, string $username, string $password)
     {
         if ($obj['state'] == AlertState::RECOVERED) {
             $alertmanager_status = 'endsAt';
@@ -74,10 +77,10 @@ class Alertmanager extends Transport
             }
         }
 
-        return $this->postAlerts($url, $data);
+        return $this->postAlerts($url, $data, $username, $password);
     }
 
-    public static function postAlerts($url, $data)
+    public static function postAlerts($url, $data, string $username, string $password)
     {
         $curl = curl_init();
         Proxy::applyToCurl($curl);
@@ -89,6 +92,12 @@ class Alertmanager extends Transport
         curl_setopt($curl, CURLOPT_CONNECTTIMEOUT_MS, 5000);
         curl_setopt($curl, CURLOPT_POST, true);
 
+        if ($username != '' && $password != '') {
+            curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
+            curl_setopt($curl, CURLOPT_USERNAME, $username);
+            curl_setopt($curl, CURLOPT_PASSWORD, $password);
+        }
+
         $alert_message = json_encode($data);
         curl_setopt($curl, CURLOPT_POSTFIELDS, $alert_message);
 
@@ -133,6 +142,18 @@ class Alertmanager extends Transport
                     'descr' => 'Alertmanager Webhook URL(s). Can contain comma-separated URLs',
                     'type' => 'text',
                 ],
+                [
+                    'title' => 'Alertmanager Username',
+                    'name' => 'alertmanager-username',
+                    'descr' => 'Alertmanager Basic Username to authenticate to Alertmanager',
+                    'type' => 'text',
+                ],
+                [
+                    'title' => 'Alertmanager Password',
+                    'name' => 'alertmanager-password',
+                    'descr' => 'Alertmanager Basic Password to authenticate to Alertmanager',
+                    'type' => 'password',
+                ],
                 [
                     'title' => 'Alertmanager Options',
                     'name' => 'alertmanager-options',
diff --git a/doc/Alerting/Transports.md b/doc/Alerting/Transports.md
index d7ba461ef2..942a931505 100644
--- a/doc/Alerting/Transports.md
+++ b/doc/Alerting/Transports.md
@@ -75,6 +75,9 @@ label's value will be the string you provided just as it was a fixed string.
 Multiple Alertmanager URLs (comma separated) are supported. Each
 URL will be tried and the search will stop at the first success.
 
+Basic HTTP authentication with a username and a password is supported.
+If you let those value blank, no authentication will be used.
+
 [Alertmanager Docs](https://prometheus.io/docs/alerting/alertmanager/)
 
 **Example:**
@@ -82,6 +85,8 @@ URL will be tried and the search will stop at the first success.
 | Config | Example |
 | ------ | ------- |
 | Alertmanager URL(s)   | http://alertmanager1.example.com,http://alertmanager2.example.com |
+| Alertmanager Username | myUsername |
+| Alertmanager Password | myPassword |
 | Alertmanager Options: | source=librenms <br/> customlabel=value <br/> extra_dynamic_value=variable_name |
 
 ## API