diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -172,6 +172,8 @@
             $this->register_action('resources-owner', [$this, 'resources_owner']);
             $this->register_action('resources-calendar', [$this, 'resources_calendar']);
             $this->register_action('resources-autocomplete', [$this, 'resources_autocomplete']);
+            $this->register_action('talk-room-create', [$this, 'talk_room_create']);
+
             $this->add_hook('refresh', [$this, 'refresh']);
 
             // remove undo information...
@@ -3876,6 +3878,27 @@
         return $args;
     }
 
+    /**
+     * Create a Nextcould Talk room
+     */
+    public function talk_room_create()
+    {
+        require_once __DIR__ . '/lib/calendar_nextcloud_api.php';
+
+        $api = new calendar_nextcloud_api();
+
+        $name = (string) rcube_utils::get_input_value('_name', rcube_utils::INPUT_POST);
+
+        $room_url = $api->talk_room_create($name);
+
+        if ($room_url) {
+            $this->rc->output->command('plugin.talk_room_created', ['url' => $room_url]);
+        }
+        else {
+            $this->rc->output->command('display_message', $this->gettext('talkroomcreateerror'), 'error');
+        }
+    }
+
     /**
      * Get a list of email addresses of the current user (from login and identities)
      */
diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -3535,6 +3535,22 @@
       }
     };
 
+    /*** Nextcloud Talk integration ***/
+
+    this.talk_room_create = function()
+    {
+        var lock = rcmail.set_busy(true, 'calendar.talkroomcreating');
+
+        rcmail.http_post('talk-room-create', { _name: $('#edit-title').val() }, lock);
+    };
+
+    this.talk_room_created = function(data)
+    {
+        if (data.url) {
+            $('#edit-location').val(data.url);
+        }
+    };
+
 
     /***  startup code  ***/
 
@@ -4184,6 +4200,7 @@
   rcmail.register_command('event-sendbymail', function(p, obj, e){ cal.event_sendbymail(cal.selected_event, e); }, true);
   rcmail.register_command('event-copy', function(){ cal.event_copy(cal.selected_event); }, true);
   rcmail.register_command('event-history', function(p, obj, e){ cal.event_history_dialog(cal.selected_event); }, false);
+  rcmail.register_command('talk-room-create', function(){ cal.talk_room_create(); }, true);
 
   // search and export events
   rcmail.register_command('export', function(){ cal.export_events(cal.calendars[cal.selected_calendar]); }, true);
@@ -4211,6 +4228,7 @@
   rcmail.addEventListener('plugin.close_history_dialog', function(data){ cal.close_history_dialog(); });
   rcmail.addEventListener('plugin.event_show_revision', function(data){ cal.event_show_dialog(data, null, true); });
   rcmail.addEventListener('plugin.itip_message_processed', function(data){ cal.itip_message_processed(data); });
+  rcmail.addEventListener('plugin.talk_room_created', function(data){ cal.talk_room_created(data); });
   rcmail.addEventListener('requestrefresh', function(q){ return cal.before_refresh(q); });
 
   $(window).resize(function(e) {
diff --git a/plugins/calendar/config.inc.php.dist b/plugins/calendar/config.inc.php.dist
--- a/plugins/calendar/config.inc.php.dist
+++ b/plugins/calendar/config.inc.php.dist
@@ -151,4 +151,5 @@
 // See freebusy_session_auth in configuration of kolab_auth plugin.
 $config['calendar_freebusy_session_auth_url'] = null;
 
-?>
+// Nextcloud installation URL (for Talk integration).
+$config['calendar_nextcloud_url'] = null;
diff --git a/plugins/calendar/lib/calendar_nextcloud_api.php b/plugins/calendar/lib/calendar_nextcloud_api.php
new file mode 100644
--- /dev/null
+++ b/plugins/calendar/lib/calendar_nextcloud_api.php
@@ -0,0 +1,114 @@
+<?php
+
+/**
+ * Nextcloud API for the Calendar plugin.
+ *
+ * @author Aleksander Machniak <machniak@apheleia-it.ch>
+ *
+ * Copyright (C) Apheleia IT AG <contact@apheleia-it.ch>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+class calendar_nextcloud_api
+{
+
+    /**
+     * Make a request to the Nextcloud API
+     *
+     * @return false|array Response data or False on failure
+     */
+    protected function request($path, $method = 'GET', $params = [])
+    {
+        $rcmail = rcube::get_instance();
+
+        $url = unslashify($rcmail->config->get('calendar_nextcloud_url'));
+        $url .= "/ocs/v2.php/$path";
+
+        try {
+            $request_config = [
+                'store_body'       => true,
+                'follow_redirects' => true,
+            ];
+
+            $request = libkolab::http_request($url, $method, $request_config);
+
+            // Authentication
+            $request->setAuth(
+                $rcmail->user->get_username(),
+                $rcmail->decrypt($_SESSION['password'])
+            );
+
+            // Disable CSRF prevention, and enable JSON responses
+            $request->setHeader([
+                    'OCS-APIRequest' => 'true',
+                    'Accept' => 'application/json',
+            ]);
+
+            if (!empty($params)) {
+                $request->addPostParameter($params);
+            }
+
+            // Send the request
+            $response = $request->send();
+
+            $body = $response->getBody();
+            $code = $response->getStatus();
+
+            if ($code < 400) {
+                return json_decode($body, true);
+            }
+
+            if (strpos($body, '<?xml') === 0) {
+                $doc = new DOMDocument();
+                $doc->loadXML($body);
+                $code = $doc->getElementsByTagName('statuscode')->item(0)->textContent;
+                $msg = $doc->getElementsByTagName('message')->item(0)->textContent;
+            }
+            else {
+                $msg = 'Unknown error';
+            }
+
+            throw new Exception("Nextcloud API Error: [$code] $msg");
+        }
+        catch (Exception $e) {
+            rcube::raise_error($e, true, false);
+        }
+
+        return false;
+    }
+
+    /**
+     * Create a Talk room
+     *
+     * @return string|false Room URL
+     */
+    public function talk_room_create($name = '')
+    {
+        $rcmail = rcube::get_instance();
+
+        $params = [
+            'roomType' => 3,
+            'roomName' => $name ?: $rcmail->gettext('calendar.talkroomname'),
+        ];
+
+        $response = $this->request('apps/spreed/api/v4/room', 'POST', $params);
+
+        if (is_array($response) && !empty($response['ocs']['data']['token'])) {
+            $url = unslashify($rcmail->config->get('calendar_nextcloud_url'));
+            return $url . '/call/' . $response['ocs']['data']['token'];
+        }
+
+        return false;
+    }
+}
diff --git a/plugins/calendar/localization/en_US.inc b/plugins/calendar/localization/en_US.inc
--- a/plugins/calendar/localization/en_US.inc
+++ b/plugins/calendar/localization/en_US.inc
@@ -321,4 +321,8 @@
 $labels['arialabelresourceselection'] = 'Available resources';
 $labels['arialabeleventform'] = 'Event editing form';
 
-?>
+// Nextcloud Talk integration
+$labels['createtalkroom'] = 'Create Talk room';
+$labels['talkroomcreating'] = 'Creating a Talk room for the event...';
+$labels['talkroomcreateerror'] = 'Failed to create a Talk room.';
+$labels['talkroomname'] = 'Room for an event';
diff --git a/plugins/calendar/skins/elastic/templates/eventedit.html b/plugins/calendar/skins/elastic/templates/eventedit.html
--- a/plugins/calendar/skins/elastic/templates/eventedit.html
+++ b/plugins/calendar/skins/elastic/templates/eventedit.html
@@ -10,6 +10,9 @@
 			<div class="form-group">
 				<label for="edit-location"><roundcube:label name="calendar.location" /></label>
 				<input type="text" class="form-control" name="location" id="edit-location" size="40" />
+				<roundcube:if condition="config:calendar_nextcloud_url" />
+				<a href="#" onclick="rcmail.command('talk-room-create')" style="float:right; margin-top:0.5em;"><roundcube:label name="calendar.createtalkroom" /></a>
+				<roundcube:endif />
 			</div>
 			<div class="form-group">
 				<label for="edit-description"><roundcube:label name="calendar.description" /></label>