diff --git a/autotests/kprotocolinfotest.cpp b/autotests/kprotocolinfotest.cpp
--- a/autotests/kprotocolinfotest.cpp
+++ b/autotests/kprotocolinfotest.cpp
@@ -59,6 +59,10 @@
 
     QCOMPARE(KProtocolInfo::protocolClass(QStringLiteral("http")), QStringLiteral(":internet"));
 
+    QCOMPARE(KProtocolInfo::defaultMimetype(QStringLiteral("ftp")), QString());
+    QCOMPARE(KProtocolInfo::defaultMimetype(QStringLiteral("rtsp")), QString("audio/x-pn-realaudio"));
+    QCOMPARE(KProtocolInfo::defaultMimetype(QStringLiteral("data")), QString("application/octet-stream"));
+
     QVERIFY(KProtocolManager::supportsListing(QUrl(QStringLiteral("ftp://10.1.1.10"))));
 
     const QUrl url = QUrl::fromLocalFile(QStringLiteral("/tmp"));
diff --git a/src/core/kprotocolinfo.h b/src/core/kprotocolinfo.h
--- a/src/core/kprotocolinfo.h
+++ b/src/core/kprotocolinfo.h
@@ -231,6 +231,17 @@
      */
     static bool determineMimetypeFromExtension(const QString &protocol);
 
+    /**
+     * Returns the default mimetype for the specified protocol, if one exists.
+     *
+     * This corresponds to the "defaultMimetype=" field in the protocol description file.
+     *
+     * @param protocol the protocol to check
+     * @return the default mimetype of the protocol, or an empty string if none set or protocol unknown
+     * @since 5.60
+     */
+    static QString defaultMimetype(const QString &protocol);
+
     /**
      * Returns the documentation path for the specified protocol.
      *
diff --git a/src/core/kprotocolinfo.cpp b/src/core/kprotocolinfo.cpp
--- a/src/core/kprotocolinfo.cpp
+++ b/src/core/kprotocolinfo.cpp
@@ -316,6 +316,16 @@
     return prot->m_extraFields;
 }
 
+QString KProtocolInfo::defaultMimetype(const QString &_protocol)
+{
+    KProtocolInfoPrivate *prot = KProtocolInfoFactory::self()->findProtocol(_protocol);
+    if (!prot) {
+        return QString();
+    }
+
+    return prot->m_defaultMimetype;
+}
+
 QString KProtocolInfo::docPath(const QString &_protocol)
 {
     KProtocolInfoPrivate *prot = KProtocolInfoFactory::self()->findProtocol(_protocol);