diff --git a/esphome/core/__init__.py b/esphome/core/__init__.py
index 8bdef3a4ea..addecf1326 100644
--- a/esphome/core/__init__.py
+++ b/esphome/core/__init__.py
@@ -10,6 +10,7 @@ from esphome.const import (
     CONF_USE_ADDRESS,
     CONF_ETHERNET,
     CONF_WIFI,
+    CONF_PORT,
     KEY_CORE,
     KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
@@ -519,6 +520,19 @@ class EsphomeCore:
 
         return None
 
+    @property
+    def web_port(self) -> Optional[int]:
+        if self.config is None:
+            raise ValueError("Config has not been loaded yet")
+
+        if "web_server" in self.config:
+            try:
+                return self.config["web_server"][CONF_PORT]
+            except KeyError:
+                return 80
+
+        return None
+
     @property
     def comment(self) -> Optional[str]:
         if self.config is None:
diff --git a/esphome/dashboard/dashboard.py b/esphome/dashboard/dashboard.py
index 084dd84a07..11571ec889 100644
--- a/esphome/dashboard/dashboard.py
+++ b/esphome/dashboard/dashboard.py
@@ -509,6 +509,12 @@ class DashboardEntry:
             return None
         return self.storage.address
 
+    @property
+    def web_port(self):
+        if self.storage is None:
+            return None
+        return self.storage.web_port
+
     @property
     def name(self):
         if self.storage is None:
@@ -569,6 +575,7 @@ class ListDevicesHandler(BaseHandler):
                             "path": entry.path,
                             "comment": entry.comment,
                             "address": entry.address,
+                            "web_port": entry.web_port,
                             "target_platform": entry.target_platform,
                         }
                         for entry in entries
diff --git a/esphome/storage_json.py b/esphome/storage_json.py
index 3262559116..207a3edf57 100644
--- a/esphome/storage_json.py
+++ b/esphome/storage_json.py
@@ -41,6 +41,7 @@ class StorageJSON:
         esphome_version,
         src_version,
         address,
+        web_port,
         target_platform,
         build_path,
         firmware_bin_path,
@@ -60,6 +61,9 @@ class StorageJSON:
         self.src_version = src_version  # type: int
         # Address of the ESP, for example livingroom.local or a static IP
         self.address = address  # type: str
+        # Web server port of the ESP, for example 80
+        assert web_port is None or isinstance(web_port, int)
+        self.web_port = web_port  # type: int
         # The type of ESP in use, either ESP32 or ESP8266
         self.target_platform = target_platform  # type: str
         # The absolute path to the platformio project
@@ -78,6 +82,7 @@ class StorageJSON:
             "esphome_version": self.esphome_version,
             "src_version": self.src_version,
             "address": self.address,
+            "web_port": self.web_port,
             "esp_platform": self.target_platform,
             "build_path": self.build_path,
             "firmware_bin_path": self.firmware_bin_path,
@@ -101,6 +106,7 @@ class StorageJSON:
             esphome_version=const.__version__,
             src_version=1,
             address=esph.address,
+            web_port=esph.web_port,
             target_platform=esph.target_platform,
             build_path=esph.build_path,
             firmware_bin_path=esph.firmware_bin,
@@ -117,6 +123,7 @@ class StorageJSON:
             esphome_version=const.__version__,
             src_version=1,
             address=address,
+            web_port=None,
             target_platform=esp_platform,
             build_path=None,
             firmware_bin_path=None,
@@ -135,6 +142,7 @@ class StorageJSON:
         )
         src_version = storage.get("src_version")
         address = storage.get("address")
+        web_port = storage.get("web_port")
         esp_platform = storage.get("esp_platform")
         build_path = storage.get("build_path")
         firmware_bin_path = storage.get("firmware_bin_path")
@@ -146,6 +154,7 @@ class StorageJSON:
             esphome_version,
             src_version,
             address,
+            web_port,
             esp_platform,
             build_path,
             firmware_bin_path,