diff --git a/sky/backends/cloud_vm_ray_backend.py b/sky/backends/cloud_vm_ray_backend.py
index 8974a0129bd..99726719f1d 100644
--- a/sky/backends/cloud_vm_ray_backend.py
+++ b/sky/backends/cloud_vm_ray_backend.py
@@ -3309,7 +3309,7 @@ def error_message() -> str:
         # even if some of them raise exceptions. We should replace it with
         # multi-process.
         rich_utils.stop_safe_status()
-        subprocess_utils.run_in_parallel(_setup_node, range(num_nodes))
+        subprocess_utils.run_in_parallel(_setup_node, list(range(num_nodes)))
 
         if detach_setup:
             # Only set this when setup needs to be run outside the self._setup()
diff --git a/sky/clouds/service_catalog/__init__.py b/sky/clouds/service_catalog/__init__.py
index d28b530ff06..9c096444bfb 100644
--- a/sky/clouds/service_catalog/__init__.py
+++ b/sky/clouds/service_catalog/__init__.py
@@ -10,6 +10,7 @@
 from sky.clouds.service_catalog.constants import CATALOG_SCHEMA_VERSION
 from sky.clouds.service_catalog.constants import HOSTED_CATALOG_DIR_URL
 from sky.utils import resources_utils
+from sky.utils import subprocess_utils
 
 if typing.TYPE_CHECKING:
     from sky.clouds import cloud
@@ -31,8 +32,7 @@ def _map_clouds_catalog(clouds: CloudFilter, method_name: str, *args, **kwargs):
     if single:
         clouds = [clouds]  # type: ignore
 
-    results = []
-    for cloud in clouds:
+    def _execute_catalog_method(cloud: str):
         try:
             cloud_module = importlib.import_module(
                 f'sky.clouds.service_catalog.{cloud.lower()}_catalog')
@@ -46,7 +46,10 @@ def _map_clouds_catalog(clouds: CloudFilter, method_name: str, *args, **kwargs):
             raise AttributeError(
                 f'Module "{cloud}_catalog" does not '
                 f'implement the "{method_name}" method') from None
-        results.append(method(*args, **kwargs))
+        return method(*args, **kwargs)
+
+    results = subprocess_utils.run_in_parallel(_execute_catalog_method,
+                                               list(clouds), len(clouds))
     if single:
         return results[0]
     return results
diff --git a/sky/optimizer.py b/sky/optimizer.py
index 2f70dd39429..d22029f1dc9 100644
--- a/sky/optimizer.py
+++ b/sky/optimizer.py
@@ -1293,9 +1293,12 @@ def _fill_in_launchable_resources(
                        if resources.cloud is not None else enabled_clouds)
         # If clouds provide hints, store them for later printing.
         hints: Dict[clouds.Cloud, str] = {}
-        for cloud in clouds_list:
-            feasible_resources = cloud.get_feasible_launchable_resources(
-                resources, num_nodes=task.num_nodes)
+
+        feasible_list = subprocess_utils.run_in_parallel(
+            lambda cloud, r=resources, n=task.num_nodes:
+            (cloud, cloud.get_feasible_launchable_resources(r, n)),
+            clouds_list)
+        for cloud, feasible_resources in feasible_list:
             if feasible_resources.hint is not None:
                 hints[cloud] = feasible_resources.hint
             if len(feasible_resources.resources_list) > 0:
diff --git a/sky/provision/azure/instance.py b/sky/provision/azure/instance.py
index 229d7361e22..4e461375a14 100644
--- a/sky/provision/azure/instance.py
+++ b/sky/provision/azure/instance.py
@@ -343,7 +343,7 @@ def create_single_instance(vm_i):
         _create_vm(compute_client, vm_name, node_tags, provider_config,
                    node_config, network_interface.id)
 
-    subprocess_utils.run_in_parallel(create_single_instance, range(count))
+    subprocess_utils.run_in_parallel(create_single_instance, list(range(count)))
 
     # Update disk performance tier
     performance_tier = node_config.get('disk_performance_tier', None)
diff --git a/sky/provision/kubernetes/instance.py b/sky/provision/kubernetes/instance.py
index c431b023ab9..a849dfc3044 100644
--- a/sky/provision/kubernetes/instance.py
+++ b/sky/provision/kubernetes/instance.py
@@ -804,7 +804,8 @@ def _create_pod_thread(i: int):
 
     # Create pods in parallel
     pods = subprocess_utils.run_in_parallel(_create_pod_thread,
-                                            range(to_start_count), _NUM_THREADS)
+                                            list(range(to_start_count)),
+                                            _NUM_THREADS)
 
     # Process created pods
     for pod in pods:
diff --git a/sky/utils/subprocess_utils.py b/sky/utils/subprocess_utils.py
index 992c6bbe3ff..88d351632a3 100644
--- a/sky/utils/subprocess_utils.py
+++ b/sky/utils/subprocess_utils.py
@@ -5,7 +5,7 @@
 import resource
 import subprocess
 import time
-from typing import Any, Callable, Dict, Iterable, List, Optional, Tuple, Union
+from typing import Any, Callable, Dict, List, Optional, Tuple, Union
 
 import colorama
 import psutil
@@ -97,7 +97,7 @@ def get_parallel_threads(cloud_str: Optional[str] = None) -> int:
 
 
 def run_in_parallel(func: Callable,
-                    args: Iterable[Any],
+                    args: List[Any],
                     num_threads: Optional[int] = None) -> List[Any]:
     """Run a function in parallel on a list of arguments.
 
@@ -113,6 +113,11 @@ def run_in_parallel(func: Callable,
       A list of the return values of the function func, in the same order as the
       arguments.
     """
+    if len(args) == 0:
+        return []
+    # Short-circuit for single element
+    if len(args) == 1:
+        return [func(args[0])]
     # Reference: https://stackoverflow.com/questions/25790279/python-multiprocessing-early-termination # pylint: disable=line-too-long
     processes = num_threads if num_threads is not None else get_parallel_threads(
     )