diff --git a/.evergreen/run-csfle-tests-with-mongocryptd.sh b/.evergreen/run-csfle-tests-with-mongocryptd.sh
index a5322955ff7..8979c1759e9 100755
--- a/.evergreen/run-csfle-tests-with-mongocryptd.sh
+++ b/.evergreen/run-csfle-tests-with-mongocryptd.sh
@@ -67,6 +67,7 @@ echo "Running tests with Java ${JAVA_VERSION}"
 ./gradlew -PjavaVersion=${JAVA_VERSION} -Dorg.mongodb.test.uri=${MONGODB_URI} \
       ${GRADLE_EXTRA_VARS} \
       -Dorg.mongodb.test.fle.on.demand.credential.test.failure.enabled=true \
+      -Dorg.mongodb.test.diagnostics.thread.dump.enabled=true \
       --stacktrace --info --continue \
       driver-sync:test \
           --tests "*.Client*Encryption*" \
diff --git a/.evergreen/run-tests.sh b/.evergreen/run-tests.sh
index 0ee14ed01dc..f97ff5863a2 100755
--- a/.evergreen/run-tests.sh
+++ b/.evergreen/run-tests.sh
@@ -142,6 +142,7 @@ echo "Running tests with Java ${JAVA_VERSION}"
           ${MULTI_MONGOS_URI_SYSTEM_PROPERTY} ${API_VERSION} ${GRADLE_EXTRA_VARS} \
           ${JAVA_SYSPROP_ASYNC_TRANSPORT}  ${JAVA_SYSPROP_NETTY_SSL_PROVIDER} \
           -Dorg.mongodb.test.fle.on.demand.credential.test.failure.enabled=true \
+          -Dorg.mongodb.test.diagnostics.thread.dump.enabled=true \
           --stacktrace --info --continue ${TESTS} | tee -a logs.txt
 
 if grep -q 'LEAK:' logs.txt ; then
diff --git a/driver-core/src/test/resources/META-INF/services/org.junit.jupiter.api.extension.Extension b/driver-core/src/test/resources/META-INF/services/org.junit.jupiter.api.extension.Extension
new file mode 100644
index 00000000000..f862b0ebe84
--- /dev/null
+++ b/driver-core/src/test/resources/META-INF/services/org.junit.jupiter.api.extension.Extension
@@ -0,0 +1 @@
+com.mongodb.internal.diagnostics.ThreadDumpOnFailureExtension
diff --git a/driver-core/src/test/resources/junit-platform.properties b/driver-core/src/test/resources/junit-platform.properties
new file mode 100644
index 00000000000..6efc0d5e85c
--- /dev/null
+++ b/driver-core/src/test/resources/junit-platform.properties
@@ -0,0 +1 @@
+junit.jupiter.extensions.autodetection.enabled=true
diff --git a/driver-core/src/test/unit/com/mongodb/internal/diagnostics/ThreadDumpOnFailureExtension.java b/driver-core/src/test/unit/com/mongodb/internal/diagnostics/ThreadDumpOnFailureExtension.java
new file mode 100644
index 00000000000..6fc1036d413
--- /dev/null
+++ b/driver-core/src/test/unit/com/mongodb/internal/diagnostics/ThreadDumpOnFailureExtension.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2008-present MongoDB, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.mongodb.internal.diagnostics;
+
+import java.lang.management.ManagementFactory;
+import java.lang.management.ThreadInfo;
+import java.lang.management.ThreadMXBean;
+
+
+import com.mongodb.internal.diagnostics.logging.Logger;
+import com.mongodb.internal.diagnostics.logging.Loggers;
+
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.TestWatcher;
+
+
+/**
+ * A JUnit 5 extension that prints a thread dump to the log when a test fails.
+ *
+ * <p>The extension is auto-detected on every test run, but is inert unless explicitly enabled via the
+ * {@value #ENABLED_PROPERTY} system property. This keeps local runs quiet while allowing Evergreen (which sets the
+ * property) — or a developer who opts in with {@code -Dorg.mongodb.test.diagnostics.thread.dump.enabled=true} — to
+ * capture thread dumps for failing tests.
+ */
+public final class ThreadDumpOnFailureExtension implements TestWatcher {
+
+    static final String ENABLED_PROPERTY = "org.mongodb.test.diagnostics.thread.dump.enabled";
+
+    private static final Logger LOGGER = Loggers.getLogger(ThreadDumpOnFailureExtension.class.getSimpleName());
+
+    @Override
+    public void testFailed(final ExtensionContext context, final Throwable cause) {
+        if (!Boolean.getBoolean(ENABLED_PROPERTY)) {
+            return;
+        }
+        String testName = context.getDisplayName();
+        String threadDump = getAllThreadsDump();
+        LOGGER.error("Test failed: " + testName + "\nThread dump:\n" + threadDump);
+    }
+
+    private static String getAllThreadsDump() {
+        try {
+            final ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();
+            ThreadInfo[] threadInfos = threadMXBean.dumpAllThreads(
+                    threadMXBean.isObjectMonitorUsageSupported(),
+                    threadMXBean.isSynchronizerUsageSupported()
+            );
+            StringBuilder sb = new StringBuilder(1024);
+            for (ThreadInfo info : threadInfos) {
+                sb.append(info);
+            }
+            return sb.toString();
+        } catch (final SecurityException exc) {
+            return "Unable to get thread dump due to security manager restrictions: " + exc.getMessage();
+        }
+    }
+}