diff --git a/esphome/components/modem/__init__.py b/esphome/components/modem/__init__.py
index ca61d8ba5c..2f273c5f4f 100644
--- a/esphome/components/modem/__init__.py
+++ b/esphome/components/modem/__init__.py
@@ -7,6 +7,7 @@ from esphome.const import (
     CONF_PASSWORD,
     CONF_MODEL,
     CONF_TRIGGER_ID,
+    CONF_ON_CONNECT,
 )
 import esphome.codegen as cg
 import esphome.config_validation as cv
@@ -32,6 +33,9 @@ ModemState = modem_ns.enum("ModemState")
 ModemOnNotRespondingTrigger = modem_ns.class_(
     "ModemOnNotRespondingTrigger", automation.Trigger.template()
 )
+ModemOnConnectTrigger = modem_ns.class_(
+    "ModemOnConnectTrigger", automation.Trigger.template()
+)
 
 
 CONFIG_SCHEMA = cv.All(
@@ -55,6 +59,9 @@ CONFIG_SCHEMA = cv.All(
                     )
                 }
             ),
+            cv.Optional(CONF_ON_CONNECT): automation.validate_automation(
+                {cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ModemOnConnectTrigger)}
+            ),
         }
     ).extend(cv.COMPONENT_SCHEMA),
     cv.require_framework_version(
@@ -119,4 +126,8 @@ async def to_code(config):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(trigger, [], conf)
 
+    for conf in config.get(CONF_ON_CONNECT, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [], conf)
+
     await cg.register_component(var, config)
diff --git a/esphome/components/modem/automation.h b/esphome/components/modem/automation.h
index 52bd82e10d..4a5457f90f 100644
--- a/esphome/components/modem/automation.h
+++ b/esphome/components/modem/automation.h
@@ -20,6 +20,17 @@ class ModemOnNotRespondingTrigger : public Trigger<> {
   }
 };
 
+class ModemOnConnectTrigger : public Trigger<> {
+ public:
+  explicit ModemOnConnectTrigger(ModemComponent *parent) {
+    parent->add_on_state_callback([this, parent](ModemState state) {
+      if (!parent->is_failed() && state == ModemState::CONNECTED) {
+        this->trigger();
+      }
+    });
+  }
+};
+
 }  // namespace modem
 }  // namespace esphome
 #endif  // USE_ESP_IDF
diff --git a/esphome/components/modem/modem_component.cpp b/esphome/components/modem/modem_component.cpp
index 9bfb1a9ce1..085296110a 100644
--- a/esphome/components/modem/modem_component.cpp
+++ b/esphome/components/modem/modem_component.cpp
@@ -28,7 +28,7 @@ namespace modem {
 
 using namespace esp_modem;
 
-ModemComponent *global_modem_component;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+ModemComponent *global_modem_component = nullptr;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
 #define ESPHL_ERROR_CHECK(err, message) \
   if ((err) != ESP_OK) { \
@@ -65,7 +65,10 @@ void set_wdt(uint32_t timeout_s) {
 #endif  // ESP_IDF_VERSION_MAJOR
 }
 
-ModemComponent::ModemComponent() { global_modem_component = this; }
+ModemComponent::ModemComponent() {
+  assert(global_modem_component == nullptr);
+  global_modem_component = this;
+}
 
 void ModemComponent::dump_config() { ESP_LOGCONFIG(TAG, "Config Modem:"); }
 
@@ -293,6 +296,8 @@ void ModemComponent::loop() {
 
         this->dump_connect_params_();
         this->status_clear_warning();
+        this->on_state_callback_.call(ModemState::CONNECTED);
+
       } else if (now - this->connect_begin_ > 45000) {
         ESP_LOGW(TAG, "Connecting via Modem failed! Re-connecting...");
         this->state_ = ModemComponentState::STOPPED;