diff --git a/homeassistant/components/honeywell/__init__.py b/homeassistant/components/honeywell/__init__.py
index eb89ba2a681..6c4c7091840 100644
--- a/homeassistant/components/honeywell/__init__.py
+++ b/homeassistant/components/honeywell/__init__.py
@@ -9,17 +9,9 @@ from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_PASSWORD, CONF_USERNAME, Platform
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.exceptions import ConfigEntryAuthFailed, ConfigEntryNotReady
-from homeassistant.helpers.aiohttp_client import (
-    async_create_clientsession,
-    async_get_clientsession,
-)
+from homeassistant.helpers.aiohttp_client import async_create_clientsession
 
-from .const import (
-    _LOGGER,
-    CONF_COOL_AWAY_TEMPERATURE,
-    CONF_HEAT_AWAY_TEMPERATURE,
-    DOMAIN,
-)
+from .const import _LOGGER, CONF_COOL_AWAY_TEMPERATURE, CONF_HEAT_AWAY_TEMPERATURE
 
 UPDATE_LOOP_SLEEP_TIME = 5
 PLATFORMS = [Platform.CLIMATE, Platform.HUMIDIFIER, Platform.SENSOR, Platform.SWITCH]
@@ -56,11 +48,11 @@ async def async_setup_entry(
     username = config_entry.data[CONF_USERNAME]
     password = config_entry.data[CONF_PASSWORD]
 
-    if len(hass.config_entries.async_entries(DOMAIN)) > 1:
-        session = async_create_clientsession(hass)
-    else:
-        session = async_get_clientsession(hass)
-
+    # Always create a new session for Honeywell to prevent cookie injection
+    # issues. Even with response_url handling in aiosomecomfort 0.0.33+,
+    # cookies can still leak into other integrations when using the shared
+    # session. See issue #147395.
+    session = async_create_clientsession(hass)
     client = aiosomecomfort.AIOSomeComfort(username, password, session=session)
     try:
         await client.login()
diff --git a/homeassistant/components/honeywell/config_flow.py b/homeassistant/components/honeywell/config_flow.py
index c7cda500692..15199cdda24 100644
--- a/homeassistant/components/honeywell/config_flow.py
+++ b/homeassistant/components/honeywell/config_flow.py
@@ -16,7 +16,7 @@ from homeassistant.config_entries import (
 )
 from homeassistant.const import CONF_PASSWORD, CONF_USERNAME
 from homeassistant.core import callback
-from homeassistant.helpers.aiohttp_client import async_get_clientsession
+from homeassistant.helpers.aiohttp_client import async_create_clientsession
 
 from .const import (
     CONF_COOL_AWAY_TEMPERATURE,
@@ -114,10 +114,14 @@ class HoneywellConfigFlow(ConfigFlow, domain=DOMAIN):
 
     async def is_valid(self, **kwargs) -> bool:
         """Check if login credentials are valid."""
+        # Always create a new session for Honeywell to prevent cookie injection
+        # issues. Even with response_url handling in aiosomecomfort 0.0.33+,
+        # cookies can still leak into other integrations when using the shared
+        # session. See issue #147395.
         client = aiosomecomfort.AIOSomeComfort(
             kwargs[CONF_USERNAME],
             kwargs[CONF_PASSWORD],
-            session=async_get_clientsession(self.hass),
+            session=async_create_clientsession(self.hass),
         )
 
         await client.login()