diff --git a/src/libraries/System.Globalization/tests/System/Globalization/RegionInfoTests.cs b/src/libraries/System.Globalization/tests/System/Globalization/RegionInfoTests.cs
index 6fd30317d7f06..7a4c0c7481710 100644
--- a/src/libraries/System.Globalization/tests/System/Globalization/RegionInfoTests.cs
+++ b/src/libraries/System.Globalization/tests/System/Globalization/RegionInfoTests.cs
@@ -4,6 +4,7 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Reflection;
 using System.Tests;
 using Microsoft.DotNet.RemoteExecutor;
 using Xunit;
@@ -267,5 +268,19 @@ public void ValidateThrowingWhenUsingCustomUnspecifiedLcid()
 
             AssertExtensions.Throws<ArgumentException>("culture", () => new RegionInfo(4096));
         }
+
+        [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsNotWindows8x))]
+        public void BuiltInRegionListTest()
+        {
+            // Ensure we can create all region info objects from the built-in list
+            Dictionary<string, string> regionNames = (Dictionary<string, string>)typeof(RegionInfo).Assembly.GetType("System.Globalization.CultureData").GetProperty("RegionNames", BindingFlags.Static | BindingFlags.NonPublic).GetValue(null);
+
+            foreach (var kvp in regionNames)
+            {
+                RegionInfo ri1 = new RegionInfo(kvp.Key);
+                RegionInfo ri2 = new RegionInfo(kvp.Value == "" ? kvp.Key : kvp.Value); // invariant culture
+                Assert.Equal(ri1.Name, ri2.Name);
+            }
+        }
     }
 }
diff --git a/src/libraries/System.Private.CoreLib/src/System/Globalization/CultureData.cs b/src/libraries/System.Private.CoreLib/src/System/Globalization/CultureData.cs
index 63db5cdf58c12..bd69203950249 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Globalization/CultureData.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Globalization/CultureData.cs
@@ -164,7 +164,7 @@ internal sealed partial class CultureData
                 { "AL", "sq-AL" },
                 { "AM", "hy-AM" },
                 { "AO", "pt-AO" },
-                { "AQ", "en-A" },
+                { "AQ", "en-AQ" },
                 { "AR", "es-AR" },
                 { "AS", "en-AS" },
                 { "AT", "de-AT" },
@@ -189,7 +189,7 @@ internal sealed partial class CultureData
                 { "BR", "pt-BR" },
                 { "BS", "en-BS" },
                 { "BT", "dz-BT" },
-                { "BV", "nb-B" },
+                { "BV", "nb-BV" },
                 { "BW", "en-BW" },
                 { "BY", "be-BY" },
                 { "BZ", "en-BZ" },
@@ -202,7 +202,7 @@ internal sealed partial class CultureData
                 { "CI", "fr-CI" },
                 { "CK", "en-CK" },
                 { "CL", "es-CL" },
-                { "CM", "fr-C" },
+                { "CM", "fr-CM" },
                 { "CN", "zh-CN" },
                 { "CO", "es-CO" },
                 { "CR", "es-CR" },
@@ -245,13 +245,13 @@ internal sealed partial class CultureData
                 { "GP", "fr-GP" },
                 { "GQ", "es-GQ" },
                 { "GR", "el-GR" },
-                { "GS", "en-G" },
+                { "GS", "en-GS" },
                 { "GT", "es-GT" },
                 { "GU", "en-GU" },
                 { "GW", "pt-GW" },
                 { "GY", "en-GY" },
                 { "HK", "zh-HK" },
-                { "HM", "en-H" },
+                { "HM", "en-HM" },
                 { "HN", "es-HN" },
                 { "HR", "hr-HR" },
                 { "HT", "fr-HT" },
@@ -372,7 +372,7 @@ internal sealed partial class CultureData
                 { "SZ", "ss-SZ" },
                 { "TC", "en-TC" },
                 { "TD", "fr-TD" },
-                { "TF", "fr-T" },
+                { "TF", "fr-TF" },
                 { "TG", "fr-TG" },
                 { "TH", "th-TH" },
                 { "TJ", "tg-Cyrl-TJ" },