diff --git a/Code/Editor/CryEdit.cpp b/Code/Editor/CryEdit.cpp
index 8cede89f8a..bc96a8f3a8 100644
--- a/Code/Editor/CryEdit.cpp
+++ b/Code/Editor/CryEdit.cpp
@@ -1626,9 +1626,6 @@ bool CCryEditApp::InitInstance()
     ReflectedVarInit::setupReflection(serializeContext);
     RegisterReflectedVarHandlers();
 
-
-    QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
-
     CreateSplashScreen();
 
     // Register the application's document templates. Document templates
diff --git a/Code/Framework/AzQtComponents/AzQtComponents/Application/AzQtApplication.cpp b/Code/Framework/AzQtComponents/AzQtComponents/Application/AzQtApplication.cpp
index 594a339448..9dece6e26a 100644
--- a/Code/Framework/AzQtComponents/AzQtComponents/Application/AzQtApplication.cpp
+++ b/Code/Framework/AzQtComponents/AzQtComponents/Application/AzQtApplication.cpp
@@ -22,8 +22,6 @@ namespace AzQtComponents
          QApplication::setApplicationName("O3DE Tools Application");
 
          AzQtComponents::PrepareQtPaths();
-
-         QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
     }
 
     void AzQtApplication::InitializeDpiScaling()
diff --git a/Code/Framework/AzQtComponents/AzQtComponents/Gallery/main.cpp b/Code/Framework/AzQtComponents/AzQtComponents/Gallery/main.cpp
index 51ca2b349f..fc8af9e8ce 100644
--- a/Code/Framework/AzQtComponents/AzQtComponents/Gallery/main.cpp
+++ b/Code/Framework/AzQtComponents/AzQtComponents/Gallery/main.cpp
@@ -134,8 +134,6 @@ int main(int argc, char **argv)
     QApplication::setOrganizationDomain("o3de.org");
     QApplication::setApplicationName("O3DEWidgetGallery");
 
-    QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
-
     QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
     QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
     QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
diff --git a/Code/Framework/AzQtComponents/AzQtComponents/Tests/FloatToStringConversionTests.cpp b/Code/Framework/AzQtComponents/AzQtComponents/Tests/FloatToStringConversionTests.cpp
index da4d8de4cd..39593a1c58 100644
--- a/Code/Framework/AzQtComponents/AzQtComponents/Tests/FloatToStringConversionTests.cpp
+++ b/Code/Framework/AzQtComponents/AzQtComponents/Tests/FloatToStringConversionTests.cpp
@@ -13,54 +13,94 @@
 
 TEST(AzQtComponents, FloatToString_Truncate2Decimals)
 {
-    QLocale testLocal(QLocale::English, QLocale::UnitedStates);
+    QLocale testLocale(QLocale::English, QLocale::UnitedStates);
 
     const bool showThousandsSeparator = false;
     const int numDecimalPlaces = 2;
-    EXPECT_EQ(AzQtComponents::toString(0.1234, numDecimalPlaces, testLocal, showThousandsSeparator), "0.12");
+    EXPECT_EQ(AzQtComponents::toString(0.1234, numDecimalPlaces, testLocale, showThousandsSeparator), "0.12");
 }
 
 TEST(AzQtComponents, FloatToString_AllZerosButOne)
 {
-    QLocale testLocal(QLocale::English, QLocale::UnitedStates);
+    QLocale testLocale(QLocale::English, QLocale::UnitedStates);
 
     const bool showThousandsSeparator = false;
     int numDecimalPlaces = 2;
-    EXPECT_EQ(AzQtComponents::toString(1.0000, numDecimalPlaces, testLocal, showThousandsSeparator), "1.0");
+    EXPECT_EQ(AzQtComponents::toString(1.0000, numDecimalPlaces, testLocale, showThousandsSeparator), "1.0");
 }
 
 TEST(AzQtComponents, FloatToString_TruncateAllZerosButOne)
 {
-    QLocale testLocal(QLocale::English, QLocale::UnitedStates);
+    QLocale testLocale(QLocale::English, QLocale::UnitedStates);
 
     const bool showThousandsSeparator = false;
     int numDecimalPlaces = 2;
-    EXPECT_EQ(AzQtComponents::toString(1.0001, numDecimalPlaces, testLocal, showThousandsSeparator), "1.0");
+    EXPECT_EQ(AzQtComponents::toString(1.0001, numDecimalPlaces, testLocale, showThousandsSeparator), "1.0");
 }
 
 TEST(AzQtComponents, FloatToString_TruncateNotRound)
 {
-    QLocale testLocal(QLocale::English, QLocale::UnitedStates);
+    QLocale testLocale(QLocale::English, QLocale::UnitedStates);
 
     const bool showThousandsSeparator = false;
     int numDecimalPlaces = 3;
-    EXPECT_EQ(AzQtComponents::toString(0.1236, numDecimalPlaces, testLocal, showThousandsSeparator), "0.123");
+    EXPECT_EQ(AzQtComponents::toString(0.1236, numDecimalPlaces, testLocale, showThousandsSeparator), "0.123");
 }
 
 TEST(AzQtComponents, FloatToString_TruncateShowThousandsSeparatorTruncateNoRound)
 {
-    QLocale testLocal(QLocale::English, QLocale::UnitedStates);
+    QLocale testLocale(QLocale::English, QLocale::UnitedStates);
 
     const bool showThousandsSeparator = true;
     int numDecimalPlaces = 3;
-    EXPECT_EQ(AzQtComponents::toString(1000.1236, numDecimalPlaces, testLocal, showThousandsSeparator), "1,000.123");
+    EXPECT_EQ(AzQtComponents::toString(1000.1236, numDecimalPlaces, testLocale, showThousandsSeparator), "1,000.123");
 }
 
 TEST(AzQtComponents, FloatToString_TruncateShowThousandsSeparatorOnlyOneDecimal)
 {
-    QLocale testLocal(QLocale::English, QLocale::UnitedStates);
+    QLocale testLocale(QLocale::English, QLocale::UnitedStates);
 
     const bool showThousandsSeparator = true;
     int numDecimalPlaces = 2;
-    EXPECT_EQ(AzQtComponents::toString(1000.000, numDecimalPlaces, testLocal, showThousandsSeparator), "1,000.0");
+    EXPECT_EQ(AzQtComponents::toString(1000.000, numDecimalPlaces, testLocale, showThousandsSeparator), "1,000.0");
+}
+
+TEST(AzQtComponents, FloatToString_Truncate2DecimalsWithLocale)
+{
+    QLocale testLocale{ QLocale() };
+
+    const bool showThousandsSeparator = false;
+    const int numDecimalPlaces = 2;
+    QString testString = "0" + QString(testLocale.decimalPoint()) + "12";
+    EXPECT_EQ(testString, AzQtComponents::toString(0.1234, numDecimalPlaces, testLocale, showThousandsSeparator));
+}
+
+TEST(AzQtComponents, FloatToString_AllZerosButOneWithLocale)
+{
+    QLocale testLocale{ QLocale() };
+
+    const bool showThousandsSeparator = false;
+    const int numDecimalPlaces = 2;
+    QString testString = "1" + QString(testLocale.decimalPoint()) + "0";
+    EXPECT_EQ(testString, AzQtComponents::toString(1.0000, numDecimalPlaces, testLocale, showThousandsSeparator));
+}
+
+TEST(AzQtComponents, FloatToString_TruncateShowThousandsSeparatorTruncateNoRoundWithLocale)
+{
+    QLocale testLocale{ QLocale() };
+
+    const bool showThousandsSeparator = true;
+    const int numDecimalPlaces = 3;
+    QString testString = "1" + QString(testLocale.groupSeparator()) + "000" + QString(testLocale.decimalPoint()) + "123";
+    EXPECT_EQ(testString, AzQtComponents::toString(1000.1236, numDecimalPlaces, testLocale, showThousandsSeparator));
+}
+
+TEST(AzQtComponents, FloatToString_TruncateShowThousandsSeparatorOnlyOneDecimalWithLocale)
+{
+    QLocale testLocale{ QLocale() };
+
+    const bool showThousandsSeparator = true;
+    int numDecimalPlaces = 2;
+    QString testString = "1" + QString(testLocale.groupSeparator()) + "000" + QString(testLocale.decimalPoint()) + "0";
+    EXPECT_EQ(testString, AzQtComponents::toString(1000.000, numDecimalPlaces, testLocale, showThousandsSeparator));
 }
diff --git a/Code/Framework/AzToolsFramework/Tests/SpinBoxTests.cpp b/Code/Framework/AzToolsFramework/Tests/SpinBoxTests.cpp
index eb09c68cee..a88cb68638 100644
--- a/Code/Framework/AzToolsFramework/Tests/SpinBoxTests.cpp
+++ b/Code/Framework/AzToolsFramework/Tests/SpinBoxTests.cpp
@@ -245,12 +245,15 @@ namespace UnitTest
     {
         using testing::StrEq;
 
+        QLocale testLocale{ QLocale() };
+        QString testString = "10" + QString(testLocale.decimalPoint()) + "0";
+
         m_doubleSpinBox->setSuffix("m");
         m_doubleSpinBox->setValue(10.0);
 
         // test internal logic (textFromValue() calls private StringValue())
         QString value = m_doubleSpinBox->textFromValue(10.0);
-        EXPECT_THAT(value.toUtf8().constData(), StrEq("10.0"));
+        EXPECT_THAT(value.toUtf8().constData(), testString);
 
         m_doubleSpinBox->setFocus();
         EXPECT_THAT(m_doubleSpinBox->suffix().toUtf8().constData(), StrEq(""));
@@ -293,31 +296,44 @@ namespace UnitTest
 
     TEST_F(SpinBoxFixture, SpinBoxCheckHighValueTruncatesCorrectly)
     {
-        QString value = setupTruncationTest("0.9999999");
+        QLocale testLocale{ QLocale() };
+        QString testString = "0" + QString(testLocale.decimalPoint()) + "9999999";
+        QString value = setupTruncationTest(testString);
 
-        EXPECT_TRUE(value == "0.999");
+        testString = "0" + QString(testLocale.decimalPoint()) + "999";
+        EXPECT_TRUE(value == testString);
     }
 
     TEST_F(SpinBoxFixture, SpinBoxCheckLowValueTruncatesCorrectly)
     {
-        QString value = setupTruncationTest("0.0000001");
+        QLocale testLocale{ QLocale() };
+        QString testString = "0" + QString(testLocale.decimalPoint()) + "0000001";
+        QString value = setupTruncationTest(testString);
 
-        EXPECT_TRUE(value == "0.0");
+        testString = "0" + QString(testLocale.decimalPoint()) + "0";
+        EXPECT_TRUE(value == testString);
     }
 
     TEST_F(SpinBoxFixture, SpinBoxCheckBugValuesTruncatesCorrectly)
     {
-        QString value = setupTruncationTest("0.12395");
+        QLocale testLocale{ QLocale() };
+        QString testString = "0" + QString(testLocale.decimalPoint()) + "12395";
+        QString value = setupTruncationTest(testString);
 
-        EXPECT_TRUE(value == "0.123");
+        testString = "0" + QString(testLocale.decimalPoint()) + "123";
+        EXPECT_TRUE(value == testString);
 
-        value = setupTruncationTest("0.94496");
+        testString = "0" + QString(testLocale.decimalPoint()) + "94496";
+        value = setupTruncationTest(testString);
 
-        EXPECT_TRUE(value == "0.944");
+        testString = "0" + QString(testLocale.decimalPoint()) + "944";
+        EXPECT_TRUE(value == testString);
 
-        value = setupTruncationTest("0.0009999");
+        testString = "0" + QString(testLocale.decimalPoint()) + "0009999";
+        value = setupTruncationTest(testString);
 
-        EXPECT_TRUE(value == "0.0");
+        testString = "0" + QString(testLocale.decimalPoint()) + "0";
+        EXPECT_TRUE(value == testString);
     }
 
 } // namespace UnitTest
diff --git a/Code/Tools/ProjectManager/Source/Application.cpp b/Code/Tools/ProjectManager/Source/Application.cpp
index bdcb59897b..c977698152 100644
--- a/Code/Tools/ProjectManager/Source/Application.cpp
+++ b/Code/Tools/ProjectManager/Source/Application.cpp
@@ -56,8 +56,6 @@ namespace O3DE::ProjectManager
         QCoreApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
         QCoreApplication::setAttribute(Qt::AA_DontCreateNativeWidgetSiblings);
 
-        QLocale::setDefault(QLocale(QLocale::English, QLocale::UnitedStates));
-
         QGuiApplication::setHighDpiScaleFactorRoundingPolicy(Qt::HighDpiScaleFactorRoundingPolicy::PassThrough);
         AzQtComponents::Utilities::HandleDpiAwareness(AzQtComponents::Utilities::SystemDpiAware);