diff --git a/autotests/kurifiltertest.cpp b/autotests/kurifiltertest.cpp
--- a/autotests/kurifiltertest.cpp
+++ b/autotests/kurifiltertest.cpp
@@ -25,7 +25,7 @@
 
 #include <QtTestWidgets>
 #include <QDir>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QHostInfo>
 
 #include <iostream>
@@ -111,7 +111,7 @@
 
         if (!expectedResult.isEmpty()) {
             // Hack for other locales than english, normalize google hosts to google.com
-            cmd.replace(QRegExp(QStringLiteral("www\\.google\\.[^/]*/")), QStringLiteral("www.google.com/"));
+            cmd.replace(QRegularExpression(QStringLiteral("www\\.google\\.[^/]*/")), QStringLiteral("www.google.com/"));
             if (cmd != expectedResult) {
                 qWarning() << a;
                 QCOMPARE(cmd, expectedResult);
diff --git a/src/core/kprotocolmanager.cpp b/src/core/kprotocolmanager.cpp
--- a/src/core/kprotocolmanager.cpp
+++ b/src/core/kprotocolmanager.cpp
@@ -44,6 +44,7 @@
 #include <QDBusInterface>
 #include <QCache>
 #include <QLocale>
+#include <QRegularExpression>
 #include <qstandardpaths.h>
 #include <qmimedatabase.h>
 
@@ -900,9 +901,9 @@
 
             // Clean up unnecessary separators that could be left over from the
             // possible keyword removal above...
-            agentStr.replace(QRegExp(QL1S("[(]\\s*[;]\\s*")), QStringLiteral("("));
-            agentStr.replace(QRegExp(QL1S("[;]\\s*[;]\\s*")), QStringLiteral("; "));
-            agentStr.replace(QRegExp(QL1S("\\s*[;]\\s*[)]")), QStringLiteral(")"));
+            agentStr.replace(QRegularExpression(QStringLiteral("[(]\\s*[;]\\s*")), QStringLiteral("("));
+            agentStr.replace(QRegularExpression(QStringLiteral("[;]\\s*[;]\\s*")), QStringLiteral("; "));
+            agentStr.replace(QRegularExpression(QStringLiteral("\\s*[;]\\s*[)]")), QStringLiteral(")"));
         } else {
             agentStr.remove(QStringLiteral("%osname%"));
             agentStr.remove(QStringLiteral("%osversion%"));
diff --git a/src/core/krecentdocument.cpp b/src/core/krecentdocument.cpp
--- a/src/core/krecentdocument.cpp
+++ b/src/core/krecentdocument.cpp
@@ -39,7 +39,7 @@
 #include <kdesktopfile.h>
 #include <QDir>
 #include <QCoreApplication>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <qplatformdefs.h>
 
 #include <kconfiggroup.h>
@@ -101,7 +101,7 @@
     }
 
     QString openStr = url.toDisplayString();
-    openStr.replace(QRegExp(QStringLiteral("\\$")), QStringLiteral("$$"));   // Desktop files with type "Link" are $-variable expanded
+    openStr.replace(QRegularExpression(QStringLiteral("\\$")), QStringLiteral("$$"));   // Desktop files with type "Link" are $-variable expanded
 
     // qDebug() << "KRecentDocument::add for " << openStr;
     KConfigGroup config = KSharedConfig::openConfig()->group(QByteArray("RecentDocuments"));
diff --git a/src/ioslaves/help/kio_help.cpp b/src/ioslaves/help/kio_help.cpp
--- a/src/ioslaves/help/kio_help.cpp
+++ b/src/ioslaves/help/kio_help.cpp
@@ -34,7 +34,6 @@
 #include <QFileInfo>
 #include <QFile>
 #include <QMimeDatabase>
-#include <QRegExp>
 #include <QStandardPaths>
 #include <QUrl>
 
@@ -300,7 +299,7 @@
             if (!anchor.isEmpty()) {
                 int index = 0;
                 while (true) {
-                    index = mParsed.indexOf(QRegExp(QStringLiteral("<a name=")), index);
+                    index = mParsed.indexOf(QStringLiteral("<a name="), index);
                     if (index == -1) {
                         //qDebug() << "no anchor\n";
                         break; // use whatever is the target, most likely index.html
diff --git a/src/ioslaves/http/http.cpp b/src/ioslaves/http/http.cpp
--- a/src/ioslaves/http/http.cpp
+++ b/src/ioslaves/http/http.cpp
@@ -35,7 +35,7 @@
 #include <qdom.h>
 #include <QFile>
 #include <QLibraryInfo>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QDateTime>
 #include <QBuffer>
 #include <QIODevice>
@@ -164,9 +164,9 @@
 static QString sanitizeCustomHTTPHeader(const QString &_header)
 {
     QString sanitizedHeaders;
-    const QStringList headers = _header.split(QRegExp(QStringLiteral("[\r\n]")));
+    const QVector<QStringRef> headers = _header.splitRef(QRegularExpression(QStringLiteral("[\r\n]")));
 
-    for (const QString &header : headers) {
+    for (const QStringRef &header : headers) {
         // Do not allow Request line to be specified and ignore
         // the other HTTP headers.
         if (!header.contains(QLatin1Char(':')) ||
@@ -3280,7 +3280,7 @@
                     rel = rel.mid(5, rel.length() - 6);
                     if (rel.toLower() == QLatin1String("pageservices")) {
                         //### the remove() part looks fishy!
-                        QString url = link[0].remove(QRegExp(QStringLiteral("[<>]"))).trimmed();
+                        QString url = link[0].remove(QRegularExpression(QStringLiteral("[<>]"))).trimmed();
                         setMetaData(QStringLiteral("PageServices"), url);
                     }
                 }
@@ -3296,12 +3296,12 @@
                                      .split(QLatin1Char('='), QString::SkipEmptyParts);
                 if (policy.count() == 2) {
                     if (policy[0].toLower() == QLatin1String("policyref")) {
-                        policyrefs << policy[1].remove(QRegExp(QStringLiteral("[\")\']"))).trimmed();
+                        policyrefs << policy[1].remove(QRegularExpression(QStringLiteral("[\")\']"))).trimmed();
                     } else if (policy[0].toLower() == QLatin1String("cp")) {
                         // We convert to cp\ncp\ncp\n[...]\ncp to be consistent with
                         // other metadata sent in strings.  This could be a bit more
                         // efficient but I'm going for correctness right now.
-                        const QString s = policy[1].remove(QRegExp(QStringLiteral("[\")\']")));
+                        const QString s = policy[1].remove(QRegularExpression(QStringLiteral("[\")\']")));
                         const QStringList cps = s.split(QLatin1Char(' '), QString::SkipEmptyParts);
                         compact << cps;
                     }
@@ -3367,7 +3367,7 @@
         if (tIt.hasNext()) {
             // Now we have to check to see what is offered for the upgrade
             QString offered = toQString(tIt.next());
-            upgradeOffers = offered.split(QRegExp(QStringLiteral("[ \n,\r\t]")), QString::SkipEmptyParts);
+            upgradeOffers = offered.split(QRegularExpression(QStringLiteral("[ \n,\r\t]")), QString::SkipEmptyParts);
         }
         for (const QString &opt : qAsConst(upgradeOffers)) {
             if (opt == QLatin1String("TLS/1.0")) {
diff --git a/src/ioslaves/http/kcookiejar/kcookiejar.cpp b/src/ioslaves/http/kcookiejar/kcookiejar.cpp
--- a/src/ioslaves/http/kcookiejar/kcookiejar.cpp
+++ b/src/ioslaves/http/kcookiejar/kcookiejar.cpp
@@ -43,7 +43,7 @@
 
 #include <QString>
 #include <QFile>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QTextStream>
 #include <QLocale>
 #include <QUrl>
@@ -629,7 +629,8 @@
         return;
     }
     // Return numeric IPv4 addresses as is...
-    if (_fqdn[0] >= QL1C('0') && _fqdn[0] <= QL1C('9') && _fqdn.indexOf(QRegExp(QStringLiteral(IP_ADDRESS_EXPRESSION))) > -1) {
+    if (_fqdn[0] >= QL1C('0') && _fqdn[0] <= QL1C('9')
+        && _fqdn.indexOf(QRegularExpression(QStringLiteral(IP_ADDRESS_EXPRESSION))) > -1) {
         _domains.append(_fqdn);
         return;
     }
diff --git a/src/kpac/script.cpp b/src/kpac/script.cpp
--- a/src/kpac/script.cpp
+++ b/src/kpac/script.cpp
@@ -21,7 +21,7 @@
 #include "script.h"
 
 #include <QString>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QDateTime>
 #include <QUrl>
 
@@ -314,8 +314,9 @@
 // @returns true if @p str matches the shell @p pattern
 Q_INVOKABLE QJSValue ShExpMatch(QString str, QString patternStr)
 {
-    QRegExp pattern(patternStr, Qt::CaseSensitive, QRegExp::Wildcard);
-    return QJSValue(pattern.exactMatch(str));
+    const QRegularExpression pattern(QRegularExpression::anchoredPattern(
+                                      QRegularExpression::wildcardToRegularExpression(patternStr)));
+    return QJSValue(pattern.match(str).hasMatch());
 }
 
 // weekdayRange(day [, "GMT" ])
diff --git a/src/urifilters/localdomain/localdomainurifilter.h b/src/urifilters/localdomain/localdomainurifilter.h
--- a/src/urifilters/localdomain/localdomainurifilter.h
+++ b/src/urifilters/localdomain/localdomainurifilter.h
@@ -23,7 +23,7 @@
 
 #include <KUriFilter>
 
-#include <QRegExp>
+#include <QRegularExpression>
 
 class QHostInfo;
 class QEventLoop;
@@ -45,7 +45,7 @@
 private:
     bool exists(const QString &) const;
 
-    QRegExp m_hostPortPattern;
+    QRegularExpression m_hostPortPattern;
 };
 
 #endif
diff --git a/src/urifilters/localdomain/localdomainurifilter.cpp b/src/urifilters/localdomain/localdomainurifilter.cpp
--- a/src/urifilters/localdomain/localdomainurifilter.cpp
+++ b/src/urifilters/localdomain/localdomainurifilter.cpp
@@ -30,8 +30,6 @@
 #define QL1C(x)   QLatin1Char(x)
 #define QL1S(x)   QLatin1String(x)
 
-#define HOSTPORT_PATTERN "[a-zA-Z0-9][a-zA-Z0-9+-]*(?:\\:[0-9]{1,5})?(?:/[\\w:@&=+$,-.!~*'()]*)*"
-
 namespace {
 QLoggingCategory category("org.kde.kurifilter-localdomain", QtWarningMsg);
 }
@@ -42,8 +40,9 @@
  */
 LocalDomainUriFilter::LocalDomainUriFilter(QObject *parent, const QVariantList & /*args*/)
     : KUriFilterPlugin(QStringLiteral("localdomainurifilter"), parent)
-    , m_hostPortPattern(QL1S(HOSTPORT_PATTERN))
 {
+    m_hostPortPattern = QRegularExpression(QRegularExpression::anchoredPattern(
+         QStringLiteral("[a-zA-Z0-9][a-zA-Z0-9+-]*(?:\\:[0-9]{1,5})?(?:/[\\w:@&=+$,-.!~*'()]*)*")));
 }
 
 bool LocalDomainUriFilter::filterUri(KUriFilterData &data) const
@@ -54,7 +53,7 @@
     // When checking for local domain just validate it is indeed a local domain,
     // but do not modify the hostname! See bug#
     if ((protocol.isEmpty() || !KProtocolInfo::isKnownProtocol(protocol))
-        && m_hostPortPattern.exactMatch(data.typedString())) {
+        && m_hostPortPattern.match(data.typedString()).hasMatch()) {
         QString host(data.typedString().left(data.typedString().indexOf(QL1C('/'))));
         const int pos = host.indexOf(QL1C(':'));
         if (pos > -1) {
diff --git a/src/urifilters/shorturi/kshorturifilter.h b/src/urifilters/shorturi/kshorturifilter.h
--- a/src/urifilters/shorturi/kshorturifilter.h
+++ b/src/urifilters/shorturi/kshorturifilter.h
@@ -24,7 +24,7 @@
 #define KSHORTURIFILTER_H
 
 #include <QList>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QVariant>
 
 #include <kurifilter.h>
@@ -98,13 +98,13 @@
         }
 
         URLHint(const QString &r, const QString &p, KUriFilterData::UriTypes t = KUriFilterData::NetProtocol)
-            : regexp(QRegExp(r))
+            : hintRe(r)
             , prepend(p)
             , type(t)
         {
         }
 
-        QRegExp regexp; // if this matches, then...
+        QRegularExpression hintRe; // if this matches, then...
         QString prepend; // ...prepend this to the url
         KUriFilterData::UriTypes type;
     };
diff --git a/src/urifilters/shorturi/kshorturifilter.cpp b/src/urifilters/shorturi/kshorturifilter.cpp
--- a/src/urifilters/shorturi/kshorturifilter.cpp
+++ b/src/urifilters/shorturi/kshorturifilter.cpp
@@ -432,12 +432,11 @@
 
     // Short url matches
     if (!cmd.contains(QLatin1Char(' '))) {
-        // Okay this is the code that allows users to supply custom matches for
-        // specific URLs using Qt's regexp class. This is hard-coded for now.
-        // TODO: Make configurable at some point...
+        // Okay this is the code that allows users to supply custom matches for specific
+        // URLs using Qt's QRegularExpression class.
         for (const URLHint &hint : qAsConst(m_urlHints)) {
             qCDebug(category) << "testing regexp for" << hint.prepend;
-            if (hint.regexp.indexIn(cmd) == 0) {
+            if (hint.hintRe.match(cmd).capturedStart() == 0) {
                 const QString cmdStr = hint.prepend + cmd;
                 QUrl url(cmdStr);
                 qCDebug(category) << "match - prepending" << hint.prepend << "->" << cmdStr << "->" << url;
diff --git a/src/widgets/jobuidelegate.cpp b/src/widgets/jobuidelegate.cpp
--- a/src/widgets/jobuidelegate.cpp
+++ b/src/widgets/jobuidelegate.cpp
@@ -38,6 +38,7 @@
 #include <QPointer>
 #include <QWidget>
 #include <QIcon>
+#include <QRegularExpression>
 #include <QUrl>
 
 #include "kio/scheduler.h"
@@ -216,7 +217,7 @@
                 QString path = url.path();
                 // HACK (#98983): remove "0-foo". Note that it works better than
                 // displaying KFileItem::name(), for files under a subdir.
-                path.remove(QRegExp(QStringLiteral("^/[0-9]*-")));
+                path.remove(QRegularExpression(QStringLiteral("^/[0-9]*-")));
                 prettyList.append(path);
             } else {
                 prettyList.append(url.toDisplayString(QUrl::PreferLocalFile));
diff --git a/src/widgets/kurlcompletion.cpp b/src/widgets/kurlcompletion.cpp
--- a/src/widgets/kurlcompletion.cpp
+++ b/src/widgets/kurlcompletion.cpp
@@ -30,7 +30,7 @@
 #include <limits.h>
 
 #include <QMutex>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QDir>
 #include <QDirIterator>
 #include <QFile>
@@ -496,11 +496,11 @@
     }
 
     // Look for a protocol in 'url'
-    QRegExp protocol_regex = QRegExp(QStringLiteral("^(?![A-Za-z]:)[^/\\s\\\\]*:"));
+    const QRegularExpression protocol_regex(QStringLiteral("^(?![A-Za-z]:)[^/\\s\\\\]*:"));
 
     // Assume "file:" or whatever is given by 'cwd' if there is
     // no protocol.  (QUrl does this only for absolute paths)
-    if (protocol_regex.indexIn(url_copy) == 0) {
+    if (protocol_regex.match(url_copy).hasMatch()) {
         m_kurl = QUrl(url_copy);
         m_isURL = true;
     } else { // relative path or ~ or $something
diff --git a/src/widgets/previewjob.cpp b/src/widgets/previewjob.cpp
--- a/src/widgets/previewjob.cpp
+++ b/src/widgets/previewjob.cpp
@@ -40,7 +40,7 @@
 #include <QImage>
 #include <QPixmap>
 #include <QTimer>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <qtemporaryfile.h>
 #include <qsavefile.h>
 
@@ -339,7 +339,7 @@
             QMap<QString, KService::Ptr>::ConstIterator pluginIt = mimeMap.constFind(mimeType);
             if (pluginIt == mimeMap.constEnd()) {
                 QString groupMimeType = mimeType;
-                groupMimeType.replace(QRegExp(QStringLiteral("/.*")), QStringLiteral("/*"));
+                groupMimeType.replace(QRegularExpression(QStringLiteral("/.*")), QStringLiteral("/*"));
                 pluginIt = mimeMap.constFind(groupMimeType);
 
                 if (pluginIt == mimeMap.constEnd()) {