diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
index 75f3bc4c79eb..b8fbfafa6fcd 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
@@ -21,6 +21,7 @@
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.oas.models.servers.Server;
+import io.swagger.v3.oas.models.security.SecurityRequirement;
 import lombok.Getter;
 import lombok.Setter;
 import org.openapitools.codegen.*;
@@ -29,6 +30,7 @@
 import org.openapitools.codegen.model.ModelsMap;
 import org.openapitools.codegen.utils.ModelUtils;
 import org.openapitools.codegen.utils.ProcessUtils;
+import org.openapitools.codegen.model.OperationsMap;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -1026,9 +1028,68 @@ public CodegenOperation fromOperation(String path,
             SortParametersByRequiredFlag(op.allParams);
         }
 
+        if (GENERICHOST.equals(getLibrary())) {
+            addGenericHostSelectedSecurityRequirementNames(op, operation);
+        }
+
         return op;
     }
 
+    private void addGenericHostSelectedSecurityRequirementNames(CodegenOperation op, Operation operation) {
+        List<SecurityRequirement> securityRequirements = operation.getSecurity() != null
+                ? operation.getSecurity()
+                : openAPI.getSecurity();
+
+        if (securityRequirements == null || securityRequirements.isEmpty()) {
+            return;
+        }
+
+        SecurityRequirement selectedSecurityRequirement = securityRequirements.get(0);
+
+        if (selectedSecurityRequirement == null || selectedSecurityRequirement.isEmpty()) {
+            op.vendorExtensions.put("x-csharp-generichost-selected-auth-names", Collections.emptySet());
+            return;
+        }
+
+        op.vendorExtensions.put("x-csharp-generichost-selected-auth-names", selectedSecurityRequirement.keySet());
+    }
+
+    private void filterGenericHostAuthMethodsForSelectedSecurityRequirement(CodegenOperation op) {
+        if (op.authMethods == null || op.authMethods.isEmpty()) {
+            return;
+        }
+
+        Object selectedAuthNamesObject = op.vendorExtensions.get("x-csharp-generichost-selected-auth-names");
+
+        if (!(selectedAuthNamesObject instanceof Set<?>)) {
+            return;
+        }
+
+        Set<?> selectedAuthNames = (Set<?>) selectedAuthNamesObject;
+
+        op.authMethods = op.authMethods.stream()
+                .filter(authMethod -> selectedAuthNames.contains(authMethod.name))
+                .collect(Collectors.toList());
+
+        op.hasAuthMethods = !op.authMethods.isEmpty();
+    }
+
+    @Override
+    public OperationsMap postProcessOperationsWithModels(OperationsMap objs, List<ModelMap> allModels) {
+        OperationsMap operationsMap = super.postProcessOperationsWithModels(objs, allModels);
+
+        if (GENERICHOST.equals(getLibrary())
+                && operationsMap != null
+                && operationsMap.getOperations() != null
+                && operationsMap.getOperations().getOperation() != null) {
+            for (CodegenOperation op : operationsMap.getOperations().getOperation()) {
+                filterGenericHostAuthMethodsForSelectedSecurityRequirement(op);
+            }
+        }
+
+        return operationsMap;
+    }
+
     public void addSupportingFiles(final String clientPackageDir, final String packageFolder,
                                    final AtomicReference<Boolean> excludeTests, final String testPackageFolder, final String testPackageName, final String modelPackageDir, final String authPackageDir) {
         final String library = getLibrary();
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java
index a8c077a010e9..15fb1779869e 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java
@@ -293,4 +293,36 @@ private List<String> getNames(List<CodegenProperty> props) {
         if (props == null) return null;
         return props.stream().map(v -> v.name).collect(Collectors.toList());
     }
+
+    @Test
+    public void testGenericHostUsesOnlyFirstSecurityRequirementForOrApiKeys() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec(
+                "src/test/resources/3_0/csharp/security-or-api-key.yaml");
+
+        final DefaultGenerator defaultGenerator = new DefaultGenerator();
+        final ClientOptInput clientOptInput = new ClientOptInput();
+        clientOptInput.openAPI(openAPI);
+
+        CSharpClientCodegen cSharpClientCodegen = new CSharpClientCodegen();
+        cSharpClientCodegen.setLibrary("generichost");
+        cSharpClientCodegen.setOutputDir(output.getAbsolutePath());
+
+        clientOptInput.config(cSharpClientCodegen);
+        defaultGenerator.opts(clientOptInput);
+
+        Map<String, File> files = defaultGenerator.generate().stream()
+                .collect(Collectors.toMap(File::getPath, Function.identity()));
+
+        File defaultApi = files.get(Paths.get(output.getAbsolutePath(),
+                "src", "Org.OpenAPITools", "Api", "DefaultApi.cs").toString());
+
+        assertNotNull(defaultApi);
+        assertFileContains(defaultApi.toPath(), "ApiKeyProvider.GetAsync(\"X-API-Key\"");
+        assertFileContains(defaultApi.toPath(), "UseInHeader(httpRequestMessageLocalVar)");
+        assertFileNotContains(defaultApi.toPath(), "ApiKeyProvider.GetAsync(\"api-key\"");
+        assertFileNotContains(defaultApi.toPath(), "UseInQuery(");
+    }
 }
diff --git a/modules/openapi-generator/src/test/resources/3_0/csharp/security-or-api-key.yaml b/modules/openapi-generator/src/test/resources/3_0/csharp/security-or-api-key.yaml
new file mode 100644
index 000000000000..3d0fc8a9a44f
--- /dev/null
+++ b/modules/openapi-generator/src/test/resources/3_0/csharp/security-or-api-key.yaml
@@ -0,0 +1,30 @@
+openapi: 3.0.3
+info:
+  title: Security OR Api Key Test
+  version: 1.0.0
+
+servers:
+  - url: https://api.example.com
+
+security:
+  - apiKeyHeader: []
+  - apiKeyQuery: []
+
+paths:
+  /ping:
+    get:
+      operationId: ping
+      responses:
+        '200':
+          description: OK
+
+components:
+  securitySchemes:
+    apiKeyHeader:
+      type: apiKey
+      in: header
+      name: X-API-Key
+    apiKeyQuery:
+      type: apiKey
+      in: query
+      name: api-key
\ No newline at end of file