diff --git a/src/concurrent/CMakeLists.txt b/src/concurrent/CMakeLists.txt
index 7dfc9e911e6..504f8545345 100644
--- a/src/concurrent/CMakeLists.txt
+++ b/src/concurrent/CMakeLists.txt
@@ -28,6 +28,7 @@ qt_internal_add_module(Concurrent
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_USING_NAMESPACE
+        QT_USE_NODISCARD_FILE_OPEN
     LIBRARIES
         Qt::CorePrivate
     PUBLIC_LIBRARIES
diff --git a/src/corelib/CMakeLists.txt b/src/corelib/CMakeLists.txt
index c9e788054f9..8c2f62ef03b 100644
--- a/src/corelib/CMakeLists.txt
+++ b/src/corelib/CMakeLists.txt
@@ -323,6 +323,7 @@ qt_internal_add_module(Core
         QT_NO_QPAIR
         QT_NO_USING_NAMESPACE
         QT_TYPESAFE_FLAGS
+        QT_USE_NODISCARD_FILE_OPEN
     INCLUDE_DIRECTORIES
         "${CMAKE_CURRENT_BINARY_DIR}/global"
         "${CMAKE_CURRENT_BINARY_DIR}/kernel" # for moc_qobject.cpp to be found by qobject.cpp
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index eb06a950146..222c008f8a2 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -346,6 +346,7 @@ bool QInternal::activateCallbacks(Callback cb, void **parameters)
     \row \li 6.6.0 \li The qExchange() function (see \l{QT_NO_QEXCHANGE})
     \row \li 6.7.0 \li Overloads of QObject::connect that do not take a context object (see \l{QT_NO_CONTEXTLESS_CONNECT})
     \row \li 6.8.0 \li The qAsConst() function (see \l{QT_NO_QASCONST})
+    \row \li 6.8.0 \li File-related I/O classes have their \c{open()} functions marked \c{[[nodiscard]]} (see \l{QT_USE_NODISCARD_FILE_OPEN})
     \endtable
 
     Moreover, individual APIs may also get disabled as part of the
diff --git a/src/corelib/global/qtconfigmacros.h b/src/corelib/global/qtconfigmacros.h
index ee7ebca52bd..018161eac4c 100644
--- a/src/corelib/global/qtconfigmacros.h
+++ b/src/corelib/global/qtconfigmacros.h
@@ -199,6 +199,9 @@ namespace QT_NAMESPACE {}
 
 #if QT_ENABLE_STRICT_MODE_UP_TO >= QT_VERSION_CHECK(6, 8, 0)
 #  define QT_NO_QASCONST
+#  if !defined(QT_USE_NODISCARD_FILE_OPEN) && !defined(QT_NO_USE_NODISCARD_FILE_OPEN)
+#    define QT_USE_NODISCARD_FILE_OPEN
+#  endif
 #endif // 6.8.0
 #endif // QT_ENABLE_STRICT_MODE_UP_TO
 
diff --git a/src/corelib/io/qfile.cpp b/src/corelib/io/qfile.cpp
index 6da428f58c4..52188dde516 100644
--- a/src/corelib/io/qfile.cpp
+++ b/src/corelib/io/qfile.cpp
@@ -897,6 +897,8 @@ QFile::copy(const QString &fileName, const QString &newName)
     of the file name, otherwise, it won't be possible to create this
     non-existing file.
 
+    \sa QT_USE_NODISCARD_FILE_OPEN
+
     \sa QIODevice::OpenMode, setFileName()
 */
 bool QFile::open(OpenMode mode)
@@ -941,7 +943,7 @@ bool QFile::open(OpenMode mode)
     such permissions will generate warnings when the Security tab of the Properties dialog
     is opened. Granting the group all permissions granted to others avoids such warnings.
 
-    \sa QIODevice::OpenMode, setFileName()
+    \sa QIODevice::OpenMode, setFileName(), QT_USE_NODISCARD_FILE_OPEN
     \since 6.3
 */
 bool QFile::open(OpenMode mode, QFile::Permissions permissions)
@@ -998,7 +1000,7 @@ bool QFile::open(OpenMode mode, QFile::Permissions permissions)
            you cannot use this QFile with a QFileInfo.
     \endlist
 
-    \sa close()
+    \sa close(), QT_USE_NODISCARD_FILE_OPEN
 
     \b{Note for the Windows Platform}
 
@@ -1064,7 +1066,7 @@ bool QFile::open(FILE *fh, OpenMode mode, FileHandleFlags handleFlags)
     \warning Since this function opens the file without specifying the file name,
              you cannot use this QFile with a QFileInfo.
 
-    \sa close()
+    \sa close(), QT_USE_NODISCARD_FILE_OPEN
 */
 bool QFile::open(int fd, OpenMode mode, FileHandleFlags handleFlags)
 {
diff --git a/src/corelib/io/qfile.h b/src/corelib/io/qfile.h
index 1d18dd55c03..058b2fa2363 100644
--- a/src/corelib/io/qfile.h
+++ b/src/corelib/io/qfile.h
@@ -282,10 +282,10 @@ public:
     }
 #endif // QT_CONFIG(cxx17_filesystem)
 
-    bool open(OpenMode flags) override;
-    bool open(OpenMode flags, Permissions permissions);
-    bool open(FILE *f, OpenMode ioFlags, FileHandleFlags handleFlags=DontCloseHandle);
-    bool open(int fd, OpenMode ioFlags, FileHandleFlags handleFlags=DontCloseHandle);
+    QFILE_MAYBE_NODISCARD bool open(OpenMode flags) override;
+    QFILE_MAYBE_NODISCARD bool open(OpenMode flags, Permissions permissions);
+    QFILE_MAYBE_NODISCARD bool open(FILE *f, OpenMode ioFlags, FileHandleFlags handleFlags=DontCloseHandle);
+    QFILE_MAYBE_NODISCARD bool open(int fd, OpenMode ioFlags, FileHandleFlags handleFlags=DontCloseHandle);
 
     qint64 size() const override;
 
diff --git a/src/corelib/io/qfiledevice.cpp b/src/corelib/io/qfiledevice.cpp
index d3b493a1ccb..431dc65f5b8 100644
--- a/src/corelib/io/qfiledevice.cpp
+++ b/src/corelib/io/qfiledevice.cpp
@@ -168,6 +168,35 @@ void QFileDevicePrivate::setError(QFileDevice::FileError err, int errNum)
     handle is left open when the QFile object is destroyed.
  */
 
+/*!
+    \macro QT_USE_NODISCARD_FILE_OPEN
+    \macro QT_NO_USE_NODISCARD_FILE_OPEN
+    \relates QFileDevice
+    \since 6.8
+
+    File-related I/O classes (such as QFile, QSaveFile, QTemporaryFile)
+    have an \c{open()} method to open the file they act upon. It is
+    important to check the return value of the call to \c{open()}
+    before proceeding with reading or writing data into the file.
+
+    For this reason, starting with Qt 6.8, some overloads of \c{open()}
+    have been marked with the \c{[[nodiscard]]} attribute. Since this
+    change may raise warnings in existing codebases, user code can
+    opt-in or opt-out from having the attribute applied by defining
+    certain macros:
+
+    \list
+        \li If the \c{QT_USE_NODISCARD_FILE_OPEN} macro is defined,
+        overloads of \c{open()} are marked as \c{[[nodiscard]]}.
+        \li If the \c{QT_NO_USE_NODISCARD_FILE_OPEN} is defined, the
+        overloads of \c{open()} are \e{not} marked as \c{[[nodiscard]]}.
+        \li If neither macro is defined, then the default up to and
+        including Qt 6.9 is not to have the attribute. Starting from Qt 6.10,
+        the attribute is automatically applied.
+        \li If both macros are defined, the program is ill-formed.
+    \endlist
+*/
+
 #ifdef QT_NO_QOBJECT
 QFileDevice::QFileDevice()
     : QIODevice(*new QFileDevicePrivate)
diff --git a/src/corelib/io/qfiledevice.h b/src/corelib/io/qfiledevice.h
index 79788e2aafb..52740257154 100644
--- a/src/corelib/io/qfiledevice.h
+++ b/src/corelib/io/qfiledevice.h
@@ -12,6 +12,22 @@ QT_BEGIN_NAMESPACE
 class QDateTime;
 class QFileDevicePrivate;
 
+#if !defined(QT_USE_NODISCARD_FILE_OPEN) && !defined(QT_NO_USE_NODISCARD_FILE_OPEN)
+#  if QT_VERSION < QT_VERSION_CHECK(6, 10, 0)
+#    define QT_NO_USE_NODISCARD_FILE_OPEN
+#  else
+#    define QT_USE_NODISCARD_FILE_OPEN
+#  endif
+#endif
+
+#if defined(QT_USE_NODISCARD_FILE_OPEN) && defined(QT_NO_USE_NODISCARD_FILE_OPEN)
+#error "Inconsistent macro definition for nodiscard QFile::open"
+#elif defined(QT_USE_NODISCARD_FILE_OPEN)
+#define QFILE_MAYBE_NODISCARD [[nodiscard]]
+#else /* QT_NO_USE_NODISCARD_FILE_OPEN */
+#define QFILE_MAYBE_NODISCARD
+#endif
+
 class Q_CORE_EXPORT QFileDevice : public QIODevice
 {
 #ifndef QT_NO_QOBJECT
diff --git a/src/corelib/io/qsavefile.cpp b/src/corelib/io/qsavefile.cpp
index 9041775d99c..6d8918c29c6 100644
--- a/src/corelib/io/qsavefile.cpp
+++ b/src/corelib/io/qsavefile.cpp
@@ -152,7 +152,7 @@ void QSaveFile::setFileName(const QString &name)
     QIODevice::ReadWrite, QIODevice::Append, QIODevice::NewOnly and
     QIODevice::ExistingOnly are not supported at the moment.
 
-    \sa QIODevice::OpenMode, setFileName()
+    \sa QIODevice::OpenMode, setFileName(), QT_USE_NODISCARD_FILE_OPEN
 */
 bool QSaveFile::open(OpenMode mode)
 {
diff --git a/src/corelib/io/qsavefile.h b/src/corelib/io/qsavefile.h
index db8a25507c7..4dd712d4b60 100644
--- a/src/corelib/io/qsavefile.h
+++ b/src/corelib/io/qsavefile.h
@@ -39,7 +39,7 @@ public:
     QString fileName() const override;
     void setFileName(const QString &name);
 
-    bool open(OpenMode flags) override;
+    QFILE_MAYBE_NODISCARD bool open(OpenMode flags) override;
     bool commit();
 
     void cancelWriting();
diff --git a/src/corelib/io/qtemporaryfile.cpp b/src/corelib/io/qtemporaryfile.cpp
index 59f52bd082b..116c351962e 100644
--- a/src/corelib/io/qtemporaryfile.cpp
+++ b/src/corelib/io/qtemporaryfile.cpp
@@ -725,7 +725,7 @@ QTemporaryFile::~QTemporaryFile()
   return true upon success and will set the fileName() to the unique
   filename used.
 
-  \sa fileName()
+  \sa fileName(), QT_USE_NODISCARD_FILE_OPEN
 */
 
 /*!
diff --git a/src/corelib/io/qtemporaryfile.h b/src/corelib/io/qtemporaryfile.h
index 9d07e1633bb..9a4476f9d21 100644
--- a/src/corelib/io/qtemporaryfile.h
+++ b/src/corelib/io/qtemporaryfile.h
@@ -48,7 +48,7 @@ public:
     void setAutoRemove(bool b);
 
     // ### Hides open(flags)
-    bool open() { return open(QIODevice::ReadWrite); }
+    QFILE_MAYBE_NODISCARD bool open() { return open(QIODevice::ReadWrite); }
 
     QString fileName() const override;
     QString fileTemplate() const;
diff --git a/src/dbus/CMakeLists.txt b/src/dbus/CMakeLists.txt
index cefd12b986d..9c3f6d23d2c 100644
--- a/src/dbus/CMakeLists.txt
+++ b/src/dbus/CMakeLists.txt
@@ -47,6 +47,7 @@ qt_internal_add_module(DBus
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_QPAIR
+        QT_USE_NODISCARD_FILE_OPEN
     LIBRARIES
         Qt::CorePrivate
     PUBLIC_LIBRARIES
diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index 5f5ed6d66b5..87621e4c680 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -266,6 +266,7 @@ qt_internal_add_module(Gui
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_USING_NAMESPACE
+        QT_USE_NODISCARD_FILE_OPEN
         QT_QPA_DEFAULT_PLATFORM_NAME="${QT_QPA_DEFAULT_PLATFORM}"
     INCLUDE_DIRECTORIES
         ../3rdparty/VulkanMemoryAllocator
diff --git a/src/network/CMakeLists.txt b/src/network/CMakeLists.txt
index 38e653ce93b..f68198df588 100644
--- a/src/network/CMakeLists.txt
+++ b/src/network/CMakeLists.txt
@@ -62,6 +62,7 @@ qt_internal_add_module(Network
         QT_NO_CAST_TO_ASCII
         QT_NO_CAST_FROM_BYTEARRAY
         QT_NO_URL_CAST_FROM_STRING
+        QT_USE_NODISCARD_FILE_OPEN
     INCLUDE_DIRECTORIES
         kernel
     LIBRARIES
diff --git a/src/opengl/CMakeLists.txt b/src/opengl/CMakeLists.txt
index cbb2a2b338e..825e4cb71b5 100644
--- a/src/opengl/CMakeLists.txt
+++ b/src/opengl/CMakeLists.txt
@@ -39,6 +39,7 @@ qt_internal_add_module(OpenGL
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_USING_NAMESPACE
+        QT_USE_NODISCARD_FILE_OPEN
     LIBRARIES
         Qt::CorePrivate
         Qt::GuiPrivate
diff --git a/src/openglwidgets/CMakeLists.txt b/src/openglwidgets/CMakeLists.txt
index fff233dd206..af3efdf30f7 100644
--- a/src/openglwidgets/CMakeLists.txt
+++ b/src/openglwidgets/CMakeLists.txt
@@ -13,6 +13,7 @@ qt_internal_add_module(OpenGLWidgets
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_USING_NAMESPACE
+        QT_USE_NODISCARD_FILE_OPEN
     LIBRARIES
         Qt::OpenGLPrivate
         Qt::WidgetsPrivate
diff --git a/src/printsupport/CMakeLists.txt b/src/printsupport/CMakeLists.txt
index 0b13146cf9f..25aad04cafd 100644
--- a/src/printsupport/CMakeLists.txt
+++ b/src/printsupport/CMakeLists.txt
@@ -23,6 +23,7 @@ qt_internal_add_module(PrintSupport
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_USING_NAMESPACE
+        QT_USE_NODISCARD_FILE_OPEN
     INCLUDE_DIRECTORIES
         dialogs
         widgets
diff --git a/src/sql/CMakeLists.txt b/src/sql/CMakeLists.txt
index dbd7cf99bfe..0a51f62c4bc 100644
--- a/src/sql/CMakeLists.txt
+++ b/src/sql/CMakeLists.txt
@@ -26,6 +26,7 @@ qt_internal_add_module(Sql
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_USING_NAMESPACE
+        QT_USE_NODISCARD_FILE_OPEN
     LIBRARIES
         Qt::CorePrivate
     PUBLIC_LIBRARIES
diff --git a/src/testlib/CMakeLists.txt b/src/testlib/CMakeLists.txt
index bafef623d0b..2c33883c96f 100644
--- a/src/testlib/CMakeLists.txt
+++ b/src/testlib/CMakeLists.txt
@@ -65,6 +65,7 @@ qt_internal_add_module(Test
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_DATASTREAM
         QT_NO_FOREACH
+        QT_USE_NODISCARD_FILE_OPEN
         # Ensure uniform location info between release and debug builds
         QT_NO_MESSAGELOGCONTEXT
     LIBRARIES
diff --git a/src/tools/moc/CMakeLists.txt b/src/tools/moc/CMakeLists.txt
index f56156d39d3..b98b7ab4e9b 100644
--- a/src/tools/moc/CMakeLists.txt
+++ b/src/tools/moc/CMakeLists.txt
@@ -30,6 +30,7 @@ qt_internal_add_tool(${target_name}
         QT_NO_CAST_FROM_BYTEARRAY
         QT_NO_FOREACH
         QT_NO_QPAIR
+        QT_USE_NODISCARD_FILE_OPEN
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_SOURCE_DIR}
         ../../3rdparty/tinycbor/src
diff --git a/src/tools/qlalr/CMakeLists.txt b/src/tools/qlalr/CMakeLists.txt
index 89aecf2bdf1..da8b3518893 100644
--- a/src/tools/qlalr/CMakeLists.txt
+++ b/src/tools/qlalr/CMakeLists.txt
@@ -22,6 +22,7 @@ qt_internal_add_tool(${target_name}
     DEFINES
         QT_NO_FOREACH
         QT_NO_QPAIR
+        QT_USE_NODISCARD_FILE_OPEN
     LIBRARIES
         Qt::Core
         Qt::CorePrivate
diff --git a/src/tools/rcc/CMakeLists.txt b/src/tools/rcc/CMakeLists.txt
index 55d4de2e285..35a72c43fe5 100644
--- a/src/tools/rcc/CMakeLists.txt
+++ b/src/tools/rcc/CMakeLists.txt
@@ -18,6 +18,7 @@ qt_internal_add_tool(${target_name}
         QT_NO_CAST_FROM_ASCII
         QT_NO_FOREACH
         QT_RCC
+        QT_USE_NODISCARD_FILE_OPEN
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_SOURCE_DIR}
 )
diff --git a/src/tools/uic/CMakeLists.txt b/src/tools/uic/CMakeLists.txt
index 48c1a535464..9f47ec8b4b0 100644
--- a/src/tools/uic/CMakeLists.txt
+++ b/src/tools/uic/CMakeLists.txt
@@ -32,6 +32,7 @@ qt_internal_add_tool(${target_name}
     DEFINES
         QT_NO_CAST_FROM_ASCII
         QT_NO_FOREACH
+        QT_USE_NODISCARD_FILE_OPEN
         QT_UIC
     INCLUDE_DIRECTORIES
         ${CMAKE_CURRENT_SOURCE_DIR}
diff --git a/src/widgets/CMakeLists.txt b/src/widgets/CMakeLists.txt
index 2ba8e4719a7..fdef309a4ae 100644
--- a/src/widgets/CMakeLists.txt
+++ b/src/widgets/CMakeLists.txt
@@ -55,6 +55,7 @@ qt_internal_add_module(Widgets
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_USING_NAMESPACE
         QT_NO_FOREACH
+        QT_USE_NODISCARD_FILE_OPEN
     INCLUDE_DIRECTORIES
         dialogs
     LIBRARIES
diff --git a/src/xml/CMakeLists.txt b/src/xml/CMakeLists.txt
index 58c43f23849..38b52e3a086 100644
--- a/src/xml/CMakeLists.txt
+++ b/src/xml/CMakeLists.txt
@@ -14,6 +14,7 @@ qt_internal_add_module(Xml
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_FOREACH
         QT_NO_USING_NAMESPACE
+        QT_USE_NODISCARD_FILE_OPEN
     LIBRARIES
         Qt::CorePrivate
     PUBLIC_LIBRARIES