diff --git a/admin/environment.xml b/admin/environment.xml
index 4925aafb1c8..e031c7fc270 100644
--- a/admin/environment.xml
+++ b/admin/environment.xml
@@ -3923,6 +3923,8 @@
       </CUSTOM_CHECK>
       <CUSTOM_CHECK file="lib/upgradelib.php" function="check_xmlrpc_usage" level="optional">
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_oracle_usage" level="optional">
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
   <MOODLE version="4.2" requires="3.11.8">
@@ -4113,6 +4115,8 @@
       </CUSTOM_CHECK>
       <CUSTOM_CHECK file="lib/upgradelib.php" function="check_mod_assignment" level="required">
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_oracle_usage" level="optional">
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
   <MOODLE version="4.3" requires="3.11.8">
@@ -4305,6 +4309,8 @@
       </CUSTOM_CHECK>
       <CUSTOM_CHECK file="lib/upgradelib.php" function="check_db_prefix_length" level="required">
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_oracle_usage" level="optional">
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
   <MOODLE version="4.4" requires="4.1.2">
@@ -4496,6 +4502,8 @@
       </CUSTOM_CHECK>
       <CUSTOM_CHECK file="lib/upgradelib.php" function="check_db_prefix_length" level="required">
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_oracle_usage" level="optional">
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
 </COMPATIBILITY_MATRIX>
diff --git a/lang/en/admin.php b/lang/en/admin.php
index 37a2e2f22e9..51efd4e40e1 100644
--- a/lang/en/admin.php
+++ b/lang/en/admin.php
@@ -972,6 +972,7 @@ $string['opensslrecommended'] = 'Installing the optional OpenSSL library is high
 $string['opensslrequired'] = 'The OpenSSL PHP extension is now required by Moodle to provide stronger cryptographic services.';
 $string['opentowebcrawlers'] = 'Open to search engines';
 $string['optionalmaintenancemessage'] = 'Optional maintenance message';
+$string['oracledatabaseinuse'] = 'We are changing Oracle DB support in Moodle LMS. Moodle version 4.5 will be the last version that supports Oracle as a database architecture. Further information can be found <a href="https://moodle.org/mod/forum/discuss.php?d=456122" target="_blank">here</a>';
 $string['order1'] = 'First';
 $string['order2'] = 'Second';
 $string['order3'] = 'Third';
diff --git a/lib/tests/upgradelib_test.php b/lib/tests/upgradelib_test.php
index bc472165c84..e62d9c77c8d 100644
--- a/lib/tests/upgradelib_test.php
+++ b/lib/tests/upgradelib_test.php
@@ -1399,6 +1399,38 @@ class upgradelib_test extends advanced_testcase {
         }
     }
 
+    /**
+     * Test the check_oracle_usage check when the Moodle instance is not using Oracle as a database architecture.
+     *
+     * @covers ::check_oracle_usage
+     */
+    public function test_check_oracle_usage_is_not_used(): void {
+        global $CFG;
+
+        $this->resetAfterTest();
+        $CFG->dbtype = 'pgsql';
+
+        $result = new environment_results('custom_checks');
+        $this->assertNull(check_oracle_usage($result));
+    }
+
+    /**
+     * Test the check_oracle_usage check when the Moodle instance is using Oracle as a database architecture.
+     *
+     * @covers ::check_oracle_usage
+     */
+    public function test_check_oracle_usage_is_used(): void {
+        global $CFG;
+
+        $this->resetAfterTest();
+        $CFG->dbtype = 'oci';
+
+        $result = new environment_results('custom_checks');
+        $this->assertInstanceOf(environment_results::class, check_oracle_usage($result));
+        $this->assertEquals('oracle_database_usage', $result->getInfo());
+        $this->assertFalse($result->getStatus());
+    }
+
     /**
      * Data provider of usermenu items.
      *
diff --git a/lib/upgradelib.php b/lib/upgradelib.php
index 45bb85b5424..ca122bd8b3f 100644
--- a/lib/upgradelib.php
+++ b/lib/upgradelib.php
@@ -2864,3 +2864,26 @@ function check_mod_assignment(environment_results $result): ?environment_results
 
     return null;
 }
+
+/**
+ * Check whether the Oracle database is currently being used and warn if so.
+ *
+ * The Oracle database support will be removed in a future version (4.5) as it is no longer supported by PHP.
+ *
+ * @param environment_results $result object to update, if relevant
+ * @return environment_results|null updated results or null if the current database is not Oracle.
+ *
+ * @see https://tracker.moodle.org/browse/MDL-80166 for further information.
+ */
+function check_oracle_usage(environment_results $result): ?environment_results {
+    global $CFG;
+
+    // Checking database type.
+    if ($CFG->dbtype === 'oci') {
+        $result->setInfo('oracle_database_usage');
+        $result->setFeedbackStr('oracledatabaseinuse');
+        return $result;
+    }
+
+    return null;
+}