diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
index 14274d55708a..42d6d2480596 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
@@ -1093,6 +1093,11 @@ public String toModelFilename(String name) {
 
     @Override
     public String getTypeDeclaration(Schema p) {
+        // Intercept "null" explicitly to prevent complex object resolution
+        if (p != null && "null".equalsIgnoreCase(p.getType())) {
+            return "Object";
+        }
+
         Schema<?> schema = unaliasSchema(p);
         Schema<?> target = ModelUtils.isGenerateAliasAsModel() ? p : schema;
         if (ModelUtils.isArraySchema(target)) {
@@ -1866,16 +1871,32 @@ public String toExampleValue(Schema p) {
 
     @Override
     public String getSchemaType(Schema p) {
-        String openAPIType = super.getSchemaType(p);
+        if (p == null) {
+            return super.getSchemaType(p);
+        }
 
-        // don't apply renaming on types from the typeMapping
-        if (typeMapping.containsKey(openAPIType)) {
-            return typeMapping.get(openAPIType);
+        // Intercept explicit OpenAPI 3.1 type: "null" immediately
+        if ("null".equalsIgnoreCase(p.getType())) {
+            return "Object";
         }
 
+        String openAPIType = super.getSchemaType(p);
+
         if (null == openAPIType) {
             LOGGER.error("No Type defined for Schema {}", p);
+            return null;
+        }
+
+        // Intercept if openAPIType resolved to "null"
+        if ("null".equalsIgnoreCase(openAPIType)) {
+            return "Object";
+        }
+
+        // Don't apply renaming on types from the typeMapping
+        if (typeMapping.containsKey(openAPIType)) {
+            return typeMapping.get(openAPIType);
         }
+
         return toModelName(openAPIType);
     }
 
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
index dc5e1378ee6e..ef58276873bd 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java
@@ -4556,6 +4556,15 @@ public void testSwagger2TagImportRestAssured() throws IOException {
         assertThat(content)
                 .contains("import io.swagger.v3.oas.annotations.tags.*;")
                 .contains("@Tag(");
+
+    }
+
+    @Test
+    public void testNullTypeMapsToObject() {
+        final JavaClientCodegen codegen = new JavaClientCodegen();
+        Schema nullSchema = new Schema().type("null");
+        Assert.assertEquals(codegen.getSchemaType(nullSchema), "Object");
+        Assert.assertEquals(codegen.getTypeDeclaration(nullSchema), "Object");
     }
 
 }