diff --git a/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanOverrideHandler.java b/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanOverrideHandler.java
index c344d0e2c38..e9913ab44e0 100644
--- a/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanOverrideHandler.java
+++ b/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanOverrideHandler.java
@@ -69,9 +69,11 @@ class MockitoSpyBeanOverrideHandler extends AbstractMockitoBeanOverrideHandler {
 	}
 
 	private Object createSpy(String name, Object instance) {
+		SpringMockResolver.rejectUnsupportedSpyTarget(name, instance);
 		Class<?> resolvedTypeToOverride = getBeanType().resolve();
 		Assert.notNull(resolvedTypeToOverride, "Failed to resolve type to override");
 		Assert.isInstanceOf(resolvedTypeToOverride, instance);
+
 		if (Mockito.mockingDetails(instance).isSpy()) {
 			return instance;
 		}
diff --git a/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/SpringMockResolver.java b/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/SpringMockResolver.java
index 12e31cd0885..f6f71b5082f 100644
--- a/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/SpringMockResolver.java
+++ b/spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/SpringMockResolver.java
@@ -79,4 +79,25 @@ public class SpringMockResolver implements MockResolver {
 		return candidate;
 	}
 
+	/**
+	 * Reject the supplied bean if it is not a supported candidate to spy on.
+	 * <p>Specifically, this method ensures that the bean is not a Spring AOP proxy
+	 * with a non-static {@link TargetSource}.
+	 * @param beanName the name of the bean to spy on
+	 * @param bean the bean to spy on
+	 * @since 7.0
+	 * @see #getUltimateTargetObject(Object)
+	 */
+	static void rejectUnsupportedSpyTarget(String beanName, Object bean) throws IllegalStateException {
+		if (SPRING_AOP_PRESENT) {
+			if (AopUtils.isAopProxy(bean) && bean instanceof Advised advised &&
+					!advised.getTargetSource().isStatic()) {
+				throw new IllegalStateException("""
+					@MockitoSpyBean cannot be applied to bean '%s', because it is a Spring AOP proxy \
+					with a non-static TargetSource. Perhaps you have attempted to spy on a scoped proxy, \
+					which is not supported.""".formatted(beanName));
+			}
+		}
+	}
+
 }
diff --git a/spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanConfigurationErrorTests.java b/spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanConfigurationErrorTests.java
index b1d382e1729..38ee10d9615 100644
--- a/spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanConfigurationErrorTests.java
+++ b/spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/MockitoSpyBeanConfigurationErrorTests.java
@@ -20,15 +20,22 @@ import java.util.List;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.annotation.ScopedProxyMode;
 import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.stereotype.Component;
 import org.springframework.test.context.bean.override.BeanOverrideContextCustomizerTestUtils;
 
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 
 /**
  * Tests for {@link MockitoSpyBean @MockitoSpyBean}.
  *
  * @author Stephane Nicoll
+ * @author Sam Brannen
  */
 class MockitoSpyBeanConfigurationErrorTests {
 
@@ -73,6 +80,39 @@ class MockitoSpyBeanConfigurationErrorTests {
 						List.of("bean1", "bean2"));
 	}
 
+	@Test  // gh-35722
+	void mockitoSpyBeanCannotSpyOnScopedProxy() {
+		var context = new AnnotationConfigApplicationContext();
+		context.register(MyScopedProxy.class);
+		BeanOverrideContextCustomizerTestUtils.customizeApplicationContext(ScopedProxyTestCase.class, context);
+		context.refresh();
+
+		assertThatExceptionOfType(BeanCreationException.class)
+				.isThrownBy(() -> context.getBean(MyScopedProxy.class))
+				.havingRootCause()
+					.isInstanceOf(IllegalStateException.class)
+					.withMessage("""
+						@MockitoSpyBean cannot be applied to bean 'myScopedProxy', because it is a \
+						Spring AOP proxy with a non-static TargetSource. Perhaps you have attempted \
+						to spy on a scoped proxy, which is not supported.""");
+	}
+
+	@Test  // gh-35722
+	void mockitoSpyBeanCannotSpyOnSelfInjectionScopedProxy() {
+		var context = new AnnotationConfigApplicationContext();
+		context.register(MySelfInjectionScopedProxy.class);
+		BeanOverrideContextCustomizerTestUtils.customizeApplicationContext(SelfInjectionScopedProxyTestCase.class, context);
+
+		assertThatExceptionOfType(BeanCreationException.class)
+				.isThrownBy(context::refresh)
+				.havingRootCause()
+					.isInstanceOf(IllegalStateException.class)
+					.withMessage("""
+						@MockitoSpyBean cannot be applied to bean 'mySelfInjectionScopedProxy', because it \
+						is a Spring AOP proxy with a non-static TargetSource. Perhaps you have attempted \
+						to spy on a scoped proxy, which is not supported.""");
+	}
+
 
 	static class ByTypeSingleLookup {
 
@@ -88,4 +128,31 @@ class MockitoSpyBeanConfigurationErrorTests {
 
 	}
 
+	static class ScopedProxyTestCase {
+
+		@MockitoSpyBean
+		MyScopedProxy myScopedProxy;
+
+	}
+
+	static class SelfInjectionScopedProxyTestCase {
+
+		@MockitoSpyBean
+		MySelfInjectionScopedProxy mySelfInjectionScopedProxy;
+
+	}
+
+	@Component("myScopedProxy")
+	@Scope(proxyMode = ScopedProxyMode.TARGET_CLASS)
+	static class MyScopedProxy {
+	}
+
+	@Component("mySelfInjectionScopedProxy")
+	@Scope(proxyMode = ScopedProxyMode.TARGET_CLASS)
+	static class MySelfInjectionScopedProxy {
+
+		MySelfInjectionScopedProxy(MySelfInjectionScopedProxy self) {
+		}
+	}
+
 }