diff --git a/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy b/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
index 650cdd944d37..1ed3b9d9b776 100644
--- a/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
+++ b/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
@@ -1291,8 +1291,19 @@ class BeamModulePlugin implements Plugin<Project> {
 
             // hadoop uses an old version of logback with CVE reports
             // force all transitive logback deps to a newer one
-            force "ch.qos.logback:logback-classic:$logback_version"
-            force "ch.qos.logback:logback-core:$logback_version"
+            // When running tests with Java 8, use Java 8 compatible version only for test runtime configurations
+            // (not compile configurations to avoid dependency resolution failures)
+            // Only apply Java 8 compatible logback to explicit test runtime configurations, not compile/testCompile/testImplementation
+            def configName = config.getName().toLowerCase()
+            def isTestRuntimeConfig = (configName == 'testruntimeclasspath' ||
+                                      configName == 'testruntimeonly' ||
+                                      configName == 'testruntimemigration' ||
+                                      configName == 'shadowtestruntimeclasspath')
+            // Use logback 1.4.14 for Java 8 test runtime (last stable 1.4.x that supports Java 8)
+            // Logback 1.5.x requires Java 11+, so we must use 1.4.x when running tests with Java 8
+            def logbackVersionToUse = (isTestRuntimeConfig && project.findProperty('testJavaVersion') == '8') ? '1.4.14' : logback_version
+            force "ch.qos.logback:logback-classic:$logbackVersionToUse"
+            force "ch.qos.logback:logback-core:$logbackVersionToUse"
           }
         }
       }
@@ -1663,21 +1674,57 @@ class BeamModulePlugin implements Plugin<Project> {
         String ver = project.getProperty('testJavaVersion')
         def testJavaHome = project.getProperty("java${ver}Home")
 
-        // redirect java compiler to specified version for compileTestJava only
+        def cleanTestClassesTask = project.tasks.register("cleanTestClassesForJava${ver}") {
+          outputs.upToDateWhen { false }
+          doFirst {
+            project.sourceSets.test.output.classesDirs.each { dir ->
+              if (dir.exists()) {
+                project.delete(dir)
+              }
+            }
+          }
+        }
         project.tasks.compileTestJava {
           setCompileAndRuntimeJavaVersion(options.compilerArgs, ver)
+          // Validate javaHome exists before configuring fork options
+          def javaHomeFile = testJavaHome as File
+          if (!javaHomeFile.exists()) {
+            throw new GradleException("testJavaVersion=${ver} java${ver}Home directory does not exist: ${javaHomeFile}")
+          }
+          // Use setJavaVerOptions to configure fork with the correct Java version
+          // Note: setJavaVerOptions uses findProperty, but we've already validated it exists above
           project.ext.setJavaVerOptions(options, ver)
+
           if (ver == '25') {
             // TODO: Upgrade errorprone version to support Java25. Currently compile crashes
             //  java.lang.NoSuchFieldError: Class com.sun.tools.javac.code.TypeTag does not have member field
             //  'com.sun.tools.javac.code.TypeTag UNKNOWN'
             options.errorprone.enabled = false
           }
+          outputs.upToDateWhen { false }
+          dependsOn cleanTestClassesTask
+          doFirst {
+            // Ensure fork is enabled (setJavaVerOptions should have done this, but double-check as fallback)
+            if (!options.fork) {
+              options.fork = true
+              options.forkOptions.javaHome = javaHomeFile
+            }
+          }
         }
-        // redirect java runtime to specified version for running tests
         project.tasks.withType(Test).configureEach {
           useJUnit()
           executable = "${testJavaHome}/bin/java"
+          dependsOn cleanTestClassesTask
+          dependsOn project.tasks.compileTestJava
+        }
+        project.afterEvaluate {
+          project.tasks.withType(Test).configureEach { testTask ->
+            if (testJavaHome) {
+              testTask.executable = "${testJavaHome}/bin/java"
+            }
+            testTask.dependsOn cleanTestClassesTask
+            testTask.dependsOn project.tasks.compileTestJava
+          }
         }
       }