diff --git a/applets/digital-clock/plugin/clipboardmenu.cpp b/applets/digital-clock/plugin/clipboardmenu.cpp
--- a/applets/digital-clock/plugin/clipboardmenu.cpp
+++ b/applets/digital-clock/plugin/clipboardmenu.cpp
@@ -25,6 +25,7 @@
 #include <QClipboard>
 #include <QGuiApplication>
 #include <QMenu>
+#include <QRegularExpression>
 
 ClipboardMenu::ClipboardMenu(QObject *parent) : QObject(parent)
 {
@@ -75,7 +76,7 @@
 
         const QDate date = m_currentDate.date();
         const QTime time = m_currentDate.time();
-        const QRegExp rx ("[^0-9:]");
+        const QRegularExpression rx ("[^0-9:]");
         const QChar ws = QLatin1Char(' ');
         QString s;
         QAction *a;
@@ -111,7 +112,7 @@
         a = menu->addAction(s);
         a->setData(s);
         if (m_secondsIncluded) {
-            s = date.toString(Qt::SystemLocaleShortDate) + ws + time.toString(Qt::SystemLocaleLongDate).replace(rx, "");
+            s = date.toString(Qt::SystemLocaleShortDate) + ws + time.toString(Qt::SystemLocaleLongDate).remove(rx);
             a = menu->addAction(s);
             a->setData(s);
             s = date.toString(Qt::SystemLocaleShortDate) + ws + time.toString(Qt::SystemLocaleLongDate);
@@ -122,7 +123,7 @@
         a = menu->addAction(s);
         a->setData(s);
         if (m_secondsIncluded) {
-            s = date.toString(Qt::ISODate) + ws + time.toString(Qt::SystemLocaleLongDate).replace(rx, "");
+            s = date.toString(Qt::ISODate) + ws + time.toString(Qt::SystemLocaleLongDate).remove(rx);
             a = menu->addAction(s);
             a->setData(s);
             s = date.toString(Qt::ISODate) + ws + time.toString(Qt::SystemLocaleLongDate);
diff --git a/dataengines/devicenotifications/ksolidnotify.cpp b/dataengines/devicenotifications/ksolidnotify.cpp
--- a/dataengines/devicenotifications/ksolidnotify.cpp
+++ b/dataengines/devicenotifications/ksolidnotify.cpp
@@ -37,6 +37,7 @@
 
 #include <QStringList>
 #include <QProcess>
+#include <QRegularExpression>
 
 KSolidNotify::KSolidNotify(QObject *parent):
     QObject(parent)
@@ -127,9 +128,9 @@
     connect(p, static_cast<void (QProcess::*)(int,QProcess::ExitStatus)>(&QProcess::finished), [=](int,QProcess::ExitStatus) {
                 QStringList blockApps;
                 QString out(p->readAll());
-                const QStringList &pidList = out.split(QRegExp(QStringLiteral("\\s+")), QString::SkipEmptyParts);
+                const QVector<QStringRef> pidList = out.splitRef(QRegularExpression(QStringLiteral("\\s+")), QString::SkipEmptyParts);
                 KSysGuard::Processes procs;
-                Q_FOREACH (const QString &pidStr, pidList) {
+                for (const QStringRef &pidStr : pidList) {
                     int pid = pidStr.toInt();
                     if (!pid) {
                         continue;
diff --git a/dataengines/weather/ions/bbcukmet/ion_bbcukmet.cpp b/dataengines/weather/ions/bbcukmet/ion_bbcukmet.cpp
--- a/dataengines/weather/ions/bbcukmet/ion_bbcukmet.cpp
+++ b/dataengines/weather/ions/bbcukmet/ion_bbcukmet.cpp
@@ -31,6 +31,7 @@
 #include <QJsonObject>
 #include <QJsonArray>
 #include <QXmlStreamReader>
+#include <QRegularExpression>
 #include <QTimeZone>
 
 
@@ -825,8 +826,8 @@
     QString line;
     QString period;
     QString summary;
-    QRegExp high(QStringLiteral("Maximum Temperature: (-?\\d+).C"), Qt::CaseInsensitive);
-    QRegExp  low(QStringLiteral("Minimum Temperature: (-?\\d+).C"), Qt::CaseInsensitive);
+    const QRegularExpression high(QStringLiteral("Maximum Temperature: (-?\\d+).C"), QRegularExpression::CaseInsensitiveOption);
+    const QRegularExpression  low(QStringLiteral("Minimum Temperature: (-?\\d+).C"), QRegularExpression::CaseInsensitiveOption);
     while (!xml.atEnd()) {
         xml.readNext();
         if (xml.name() == QLatin1String("title")) {
@@ -840,11 +841,12 @@
 
             const QString temps = line.section(QLatin1Char(','), 1, 1);
             // Sometimes only one of min or max are reported
-            if (high.indexIn(temps) != -1) {
-                parseFloat(forecast->tempHigh, high.cap(1));
+            QRegularExpressionMatch rmatch;
+            if (temps.contains(high, &rmatch)) {
+                parseFloat(forecast->tempHigh, rmatch.captured(1));
             }
-            if (low.indexIn(temps) != -1) {
-                parseFloat(forecast->tempLow, low.cap(1));
+            if (temps.contains(low, &rmatch)) {
+                parseFloat(forecast->tempLow, rmatch.captured(1));
             }
 
             const QString summaryLC = summary.toLower();
diff --git a/ksmserver/server.cpp b/ksmserver/server.cpp
--- a/ksmserver/server.cpp
+++ b/ksmserver/server.cpp
@@ -65,7 +65,7 @@
 
 #include <QFile>
 #include <QPushButton>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QDBusConnection>
 #include <QDBusMessage>
 #include <QSocketNotifier>
@@ -668,7 +668,7 @@
         qCDebug(KSMSERVER) << fName;
         QString display = QString::fromLocal8Bit(::getenv("DISPLAY"));
         // strip the screen number from the display
-        display.remove(QRegExp(QStringLiteral("\\.[0-9]+$")));
+        display.remove(QRegularExpression(QStringLiteral("\\.[0-9]+$")));
         int i;
         while( (i = display.indexOf(QLatin1Char(':'))) >= 0)
            display[i] = '_';
@@ -751,7 +751,7 @@
     QByteArray fName = QFile::encodeName(QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation) + QLatin1Char('/') + QStringLiteral("KSMserver"));
     QString display  = QString::fromLocal8Bit(::getenv("DISPLAY"));
     // strip the screen number from the display
-    display.remove(QRegExp(QStringLiteral("\\.[0-9]+$")));
+    display.remove(QRegularExpression(QStringLiteral("\\.[0-9]+$")));
     int i;
     while( (i = display.indexOf(QLatin1Char(':'))) >= 0)
          display[i] = '_';
@@ -895,7 +895,7 @@
     config->reparseConfiguration(); // config may have changed in the KControl module
     KConfigGroup generalGroup(config, "General");
     excludeApps = generalGroup.readEntry( "excludeApps" ).toLower()
-                  .split( QRegExp( QStringLiteral("[,:]") ), QString::SkipEmptyParts );
+                  .split( QRegularExpression( QStringLiteral("[,:]") ), QString::SkipEmptyParts );
     KConfigGroup configSessionGroup(config, sessionGroup);
     int count =  configSessionGroup.readEntry( "count", 0 );
     for ( int i = 1; i <= count; i++ ) {
diff --git a/libkworkspace/kdisplaymanager.cpp b/libkworkspace/kdisplaymanager.cpp
--- a/libkworkspace/kdisplaymanager.cpp
+++ b/libkworkspace/kdisplaymanager.cpp
@@ -32,7 +32,6 @@
 #include <QDBusMetaType>
 #include <QDBusConnectionInterface>
 #include <QCoreApplication>
-#include <QRegExp>
 #include <QX11Info>
 
 #include <X11/Xauth.h>
diff --git a/libkworkspace/kworkspace.cpp b/libkworkspace/kworkspace.cpp
--- a/libkworkspace/kworkspace.cpp
+++ b/libkworkspace/kworkspace.cpp
@@ -102,7 +102,7 @@
     QByteArray fName = QFile::encodeName(QStandardPaths::writableLocation(QStandardPaths::RuntimeLocation)+"/KSMserver");
     QString display = QString::fromLocal8Bit( ::getenv(DISPLAY) );
     // strip the screen number from the display
-    display.remove(QRegExp(QStringLiteral("\\.[0-9]+$")));
+    display.remove(QRegularExpression(QStringLiteral("\\.\\d+$")));
     int i;
     while( (i = display.indexOf(':')) >= 0)
        display[i] = '_';
diff --git a/runners/calculator/calculatorrunner.cpp b/runners/calculator/calculatorrunner.cpp
--- a/runners/calculator/calculatorrunner.cpp
+++ b/runners/calculator/calculatorrunner.cpp
@@ -27,6 +27,7 @@
 #include <QJSEngine>
 #include <QGuiApplication>
 #include <QClipboard>
+#include <QRegularExpression>
 #endif
 
 #include <QIcon>
@@ -195,14 +196,14 @@
     hexSubstitutions(cmd);
     powSubstitutions(cmd);
 
-    if (cmd.contains(QRegExp(QStringLiteral("\\d+and\\d+")))) {
-         cmd.replace(QRegExp(QStringLiteral("(\\d+)and(\\d+)")), QStringLiteral("\\1&\\2"));
+    if (cmd.contains(QRegularExpression(QStringLiteral("\\d+and\\d+")))) {
+         cmd.replace(QRegularExpression(QStringLiteral("(\\d+)and(\\d+)")), QStringLiteral("\\1&\\2"));
     }
-    if (cmd.contains(QRegExp(QStringLiteral("\\d+or\\d+")))) {
-         cmd.replace(QRegExp(QStringLiteral("(\\d+)or(\\d+)")), QStringLiteral("\\1|\\2"));
+    if (cmd.contains(QRegularExpression(QStringLiteral("\\d+or\\d+")))) {
+         cmd.replace(QRegularExpression(QStringLiteral("(\\d+)or(\\d+)")), QStringLiteral("\\1|\\2"));
     }
-    if (cmd.contains(QRegExp(QStringLiteral("\\d+xor\\d+")))) {
-         cmd.replace(QRegExp(QStringLiteral("(\\d+)xor(\\d+)")), QStringLiteral("\\1^\\2"));
+    if (cmd.contains(QRegularExpression(QStringLiteral("\\d+xor\\d+")))) {
+         cmd.replace(QRegularExpression(QStringLiteral("(\\d+)xor(\\d+)")), QStringLiteral("\\1^\\2"));
     }
     #endif
 }
@@ -261,7 +262,8 @@
 
     userFriendlySubstitutions(cmd);
     #ifndef ENABLE_QALCULATE
-    cmd.replace(QRegExp(QStringLiteral("([a-zA-Z]+)")), QStringLiteral("Math.\\1")); //needed for accessing math functions like sin(),....
+    //needed for accessing math functions like sin(),....
+    cmd.replace(QRegularExpression(QStringLiteral("([a-zA-Z]+)")), QStringLiteral("Math.\\1"));
     #endif
 
     bool isApproximate = false;
diff --git a/shell/panelview.cpp b/shell/panelview.cpp
--- a/shell/panelview.cpp
+++ b/shell/panelview.cpp
@@ -31,6 +31,7 @@
 #include <QQmlEngine>
 #include <QQmlContext>
 #include <QGuiApplication>
+#include <QRegularExpression>
 #include <QTimer>
 
 #include <kactioncollection.h>
@@ -1192,7 +1193,8 @@
         if (containment()->destroyed()) {
             KConfigGroup views(m_corona->applicationConfig(), "PlasmaViews");
             for (auto grp : views.groupList()) {
-                if (grp.contains(QRegExp(QStringLiteral("Panel ") + QString::number(containment()->id()) + QStringLiteral("$")))) {
+                if (grp.contains(QRegularExpression(QStringLiteral("Panel %1$").arg(
+                                                        QString::number(containment()->id()))))) {
                     qDebug() << "Panel" << containment()->id() << "removed by user";
                     views.deleteGroup(grp);
                 }