diff --git a/cmake/QtInternalTargets.cmake b/cmake/QtInternalTargets.cmake
index 21bd645639a..dc45b57eecd 100644
--- a/cmake/QtInternalTargets.cmake
+++ b/cmake/QtInternalTargets.cmake
@@ -152,6 +152,7 @@ target_link_libraries(PlatformToolInternal INTERFACE PlatformAppInternal)
 
 qt_internal_add_global_definition(QT_NO_JAVA_STYLE_ITERATORS)
 qt_internal_add_global_definition(QT_NO_NARROWING_CONVERSIONS_IN_CONNECT)
+qt_internal_add_global_definition(QT_EXPLICIT_QFILE_CONSTRUCTION_FROM_PATH)
 
 if(WARNINGS_ARE_ERRORS)
     qt_internal_set_warnings_are_errors_flags(PlatformModuleInternal INTERFACE)
diff --git a/src/corelib/io/qfile.cpp b/src/corelib/io/qfile.cpp
index b1115ad15c0..bb4a4640174 100644
--- a/src/corelib/io/qfile.cpp
+++ b/src/corelib/io/qfile.cpp
@@ -226,6 +226,15 @@ QFile::QFile(QObject *parent)
 }
 /*!
     Constructs a new file object to represent the file with the given \a name.
+
+//! [qfile-explicit-constructor-note]
+    \note In versions up to and including Qt 6.8, this constructor is
+    implicit, for backward compatibility. Starting from Qt 6.9 this
+    constructor is unconditionally \c{explicit}. Users can force this
+    constructor to be \c{explicit} even in earlier versions of Qt by
+    defining the \c{QT_EXPLICIT_QFILE_CONSTRUCTION_FROM_PATH} macro
+    before including any Qt header.
+//! [qfile-explicit-constructor-note]
 */
 QFile::QFile(const QString &name)
     : QFileDevice(*new QFilePrivate, nullptr)
@@ -1145,6 +1154,8 @@ qint64 QFile::size() const
     \since 6.0
 
     Constructs a new file object to represent the file with the given \a name.
+
+    \include qfile.cpp qfile-explicit-constructor-note
 */
 /*!
     \fn QFile::QFile(const std::filesystem::path &name, QObject *parent)
diff --git a/src/corelib/io/qfile.h b/src/corelib/io/qfile.h
index 25f63d01c84..3ac6795495c 100644
--- a/src/corelib/io/qfile.h
+++ b/src/corelib/io/qfile.h
@@ -54,6 +54,13 @@ using ForceFilesystemPath = typename std::enable_if_t<std::is_same_v<std::filesy
 class QTemporaryFile;
 class QFilePrivate;
 
+// ### Qt 7: remove this, and make constructors always explicit.
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 9, 0)) || defined(QT_EXPLICIT_QFILE_CONSTRUCTION_FROM_PATH)
+#  define QFILE_MAYBE_EXPLICIT explicit
+#else
+#  define QFILE_MAYBE_EXPLICIT Q_IMPLICIT
+#endif
+
 class Q_CORE_EXPORT QFile : public QFileDevice
 {
 #ifndef QT_NO_QOBJECT
@@ -63,12 +70,12 @@ class Q_CORE_EXPORT QFile : public QFileDevice
 
 public:
     QFile();
-    QFile(const QString &name);
+    QFILE_MAYBE_EXPLICIT QFile(const QString &name);
 #ifdef Q_QDOC
-    QFile(const std::filesystem::path &name);
+    QFILE_MAYBE_EXPLICIT QFile(const std::filesystem::path &name);
 #elif QT_CONFIG(cxx17_filesystem)
     template<typename T, QtPrivate::ForceFilesystemPath<T> = 0>
-    QFile(const T &name) : QFile(QtPrivate::fromFilesystemPath(name))
+    QFILE_MAYBE_EXPLICIT QFile(const T &name) : QFile(QtPrivate::fromFilesystemPath(name))
     {
     }
 #endif // QT_CONFIG(cxx17_filesystem)