diff --git a/src/libraries/System.Diagnostics.Tracing/tests/BasicEventSourceTest/TestsWriteEventToListener.cs b/src/libraries/System.Diagnostics.Tracing/tests/BasicEventSourceTest/TestsWriteEventToListener.cs
index d7c7046ab693ed..97470a2ff4450e 100644
--- a/src/libraries/System.Diagnostics.Tracing/tests/BasicEventSourceTest/TestsWriteEventToListener.cs
+++ b/src/libraries/System.Diagnostics.Tracing/tests/BasicEventSourceTest/TestsWriteEventToListener.cs
@@ -452,6 +452,7 @@ public void Test_EventSourceCreatedEvents_AfterListener()
         [Theory]
         [InlineData(true)]
         [InlineData(false)]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/51382", TestPlatforms.iOS | TestPlatforms.tvOS | TestPlatforms.MacCatalyst)]
         public void Test_EventListenerThrows_ExceptionIsNotRethrownToCaller(bool setThrowOnEventWriteErrorsFlag)
         {
             TestUtilities.CheckNoEventSourcesRunning("Start");
diff --git a/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs b/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
index f2b35eb6c2cdf7..3eb65fdef00e02 100644
--- a/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
+++ b/src/libraries/System.Runtime.Extensions/tests/System/EnvironmentTests.cs
@@ -347,7 +347,7 @@ public void GetFolderPath_Unix_PersonalIsHomeAndUserProfile()
                 Assert.Equal(Environment.GetEnvironmentVariable("HOME"), Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments));
             }
             // tvOS effectively doesn't have a HOME
-            if (!PlatformDetection.IstvOS)
+            if (!PlatformDetection.IsiOS && !PlatformDetection.IstvOS)
             {
                 Assert.Equal(Environment.GetEnvironmentVariable("HOME"), Environment.GetFolderPath(Environment.SpecialFolder.UserProfile));
             }
diff --git a/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.netcoreapp.cs b/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.netcoreapp.cs
index 9d90fe7905550f..cfa17458204e57 100644
--- a/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.netcoreapp.cs
+++ b/src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.netcoreapp.cs
@@ -377,6 +377,7 @@ public static void AddAttributeToIndefiniteLengthContent()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public static void AddSigner_RSA_EphemeralKey()
         {
             using (RSA rsa = RSA.Create())
@@ -435,6 +436,7 @@ public static void AddSigner_DSA_EphemeralKey()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public static void AddSigner_ECDSA_EphemeralKey()
         {
             using (ECDsa ecdsa = ECDsa.Create())
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/tests/CollectionTests.cs b/src/libraries/System.Security.Cryptography.X509Certificates/tests/CollectionTests.cs
index e31f2c3a84a0cf..35e9ce439f28d6 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/tests/CollectionTests.cs
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/tests/CollectionTests.cs
@@ -833,6 +833,7 @@ public static void ExportMultiplePrivateKeys()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public static void CanAddMultipleCertsWithSinglePrivateKey()
         {
             using (var oneWithKey = new X509Certificate2(TestData.PfxData, TestData.PfxDataPassword, X509KeyStorageFlags.Exportable | Cert.EphemeralIfPossible))
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/tests/ExportTests.cs b/src/libraries/System.Security.Cryptography.X509Certificates/tests/ExportTests.cs
index 0051bc4da70e67..951a1329b77244 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/tests/ExportTests.cs
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/tests/ExportTests.cs
@@ -104,6 +104,7 @@ public static void ExportAsPfxVerifyPassword()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public static void ExportAsPfxWithPrivateKeyVerifyPassword()
         {
             using (var cert = new X509Certificate2(TestData.PfxData, TestData.PfxDataPassword, X509KeyStorageFlags.Exportable))
@@ -124,6 +125,7 @@ public static void ExportAsPfxWithPrivateKeyVerifyPassword()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public static void ExportAsPfxWithPrivateKey()
         {
             using (X509Certificate2 cert = new X509Certificate2(TestData.PfxData, TestData.PfxDataPassword, X509KeyStorageFlags.Exportable))
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.SingleCertGenerator.cs b/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.SingleCertGenerator.cs
index de3a5f18004e4e..3fad2b9d3beb08 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.SingleCertGenerator.cs
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.SingleCertGenerator.cs
@@ -62,6 +62,7 @@ public static IEnumerable<object[]> AllSingleCertVariations
 
         [Theory]
         [MemberData(nameof(AllSingleCertVariations))]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCertWithOneKey(SingleCertOptions options)
         {
             bool sameContainer = (options & SingleCertOptions.KeyAndCertInSameContents) != 0;
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.cs b/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.cs
index 3b83ac201e5097..c73af1ac3173a7 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.cs
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxFormatTests.cs
@@ -158,6 +158,7 @@ public void EmptyPfx_BadPassword()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_NoKeys_EncryptedNullPassword_NoMac()
         {
             using (X509Certificate2 cert = new X509Certificate2(TestData.MsCertificate))
@@ -175,6 +176,7 @@ public void OneCert_NoKeys_EncryptedNullPassword_NoMac()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_NoKeys_EncryptedEmptyPassword_NoMac()
         {
             using (X509Certificate2 cert = new X509Certificate2(TestData.MsCertificate))
@@ -196,6 +198,7 @@ public void OneCert_NoKeys_EncryptedEmptyPassword_NoMac()
         [InlineData(false, true)]
         [InlineData(true, false)]
         [InlineData(true, true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_EncryptedEmptyPassword_OneKey_EncryptedNullPassword_NoMac(bool encryptKeySafe, bool associateKey)
         {
             // This test shows that while a null or empty password will result in both
@@ -237,6 +240,7 @@ public void OneCert_EncryptedEmptyPassword_OneKey_EncryptedNullPassword_NoMac(bo
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_MismatchedKey()
         {
             string pw = nameof(OneCert_MismatchedKey);
@@ -285,6 +289,7 @@ public void OneCert_MismatchedKey()
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_TwoKeys_FirstWins(bool correctKeyFirst)
         {
             string pw = nameof(OneCert_TwoKeys_FirstWins);
@@ -356,6 +361,7 @@ public void OneCert_TwoKeys_FirstWins(bool correctKeyFirst)
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void TwoCerts_OneKey(bool certWithKeyFirst)
         {
             string pw = nameof(TwoCerts_OneKey);
@@ -400,6 +406,7 @@ public void TwoCerts_OneKey(bool certWithKeyFirst)
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_ExtraKeyWithUnknownAlgorithm()
         {
             string pw = nameof(OneCert_ExtraKeyWithUnknownAlgorithm);
@@ -445,6 +452,7 @@ public void OneCert_ExtraKeyWithUnknownAlgorithm()
         [Theory]
         [InlineData(true)]
         [InlineData(false)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_ExtraKeyBadEncoding(bool badTag)
         {
             string pw = nameof(OneCert_ExtraKeyBadEncoding);
@@ -503,6 +511,7 @@ public void OneCert_ExtraKeyBadEncoding(bool badTag)
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_NoKey_WithLocalKeyId()
         {
             string pw = nameof(OneCert_NoKey_WithLocalKeyId);
@@ -524,6 +533,7 @@ public void OneCert_NoKey_WithLocalKeyId()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void OneCert_TwentyKeys_NoMatches()
         {
             string pw = nameof(OneCert_NoKey_WithLocalKeyId);
@@ -562,6 +572,7 @@ public void OneCert_TwentyKeys_NoMatches()
         [Theory]
         [InlineData(true)]
         [InlineData(false)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void TwoCerts_TwentyKeys_NoMatches(bool msCertFirst)
         {
             string pw = nameof(OneCert_NoKey_WithLocalKeyId);
@@ -635,6 +646,7 @@ public void OneCorruptCert()
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void CertAndKey_NoLocalKeyId()
         {
             string pw = nameof(CertAndKey_NoLocalKeyId);
@@ -661,6 +673,7 @@ public void CertAndKey_NoLocalKeyId()
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void SameCertTwice_NoKeys(bool addLocalKeyId)
         {
             string pw = nameof(SameCertTwice_NoKeys);
@@ -692,6 +705,7 @@ public void SameCertTwice_NoKeys(bool addLocalKeyId)
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void TwoCerts_CrossedKeys()
         {
             string pw = nameof(TwoCerts_CrossedKeys);
@@ -766,6 +780,7 @@ public void TwoCerts_CrossedKeys()
         [InlineData(false, false)]
         [InlineData(true, false)]
         [InlineData(true, true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void CertAndKeyTwice(bool addLocalKeyId, bool crossIdentifiers)
         {
             string pw = nameof(CertAndKeyTwice);
@@ -821,6 +836,7 @@ public void CertAndKeyTwice(bool addLocalKeyId, bool crossIdentifiers)
         }
 
         [Fact]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void CertAndKeyTwice_KeysUntagged()
         {
             string pw = nameof(CertAndKeyTwice);
@@ -873,6 +889,7 @@ public void CertAndKeyTwice_KeysUntagged()
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void CertTwice_KeyOnce(bool addLocalKeyId)
         {
             string pw = nameof(CertTwice_KeyOnce);
@@ -930,6 +947,7 @@ public void CertTwice_KeyOnce(bool addLocalKeyId)
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void CertTwice_KeyOnce_OtherCertBetter(bool addLocalKeyId)
         {
             string pw = nameof(CertTwice_KeyOnce);
@@ -990,6 +1008,7 @@ public void CertTwice_KeyOnce_OtherCertBetter(bool addLocalKeyId)
         [InlineData(false, true)]
         [InlineData(true, false)]
         [InlineData(true, true)]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public void TwoCerts_TwoKeys_ManySafeContentsValues(bool invertCertOrder, bool invertKeyOrder)
         {
             string pw = nameof(TwoCerts_TwoKeys_ManySafeContentsValues);
diff --git a/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxTests.cs b/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxTests.cs
index bd853f1e098be6..1132d8d85a406b 100644
--- a/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxTests.cs
+++ b/src/libraries/System.Security.Cryptography.X509Certificates/tests/PfxTests.cs
@@ -141,6 +141,7 @@ private static void VerifyPrivateKey(RSA rsa)
 
         [Theory]
         [MemberData(nameof(StorageFlags))]
+        [SkipOnPlatform(TestPlatforms.iOS | TestPlatforms.MacCatalyst | TestPlatforms.tvOS, "The PKCS#12 Exportable flag is not supported on iOS/MacCatalyst/tvOS")]
         public static void ExportWithPrivateKey(X509KeyStorageFlags keyStorageFlags)
         {
             using (var cert = new X509Certificate2(TestData.PfxData, TestData.PfxDataPassword, X509KeyStorageFlags.Exportable | keyStorageFlags))