diff --git a/esphome/analyze_memory/__init__.py b/esphome/analyze_memory/__init__.py
index f56d720ec2a..33854ac2896 100644
--- a/esphome/analyze_memory/__init__.py
+++ b/esphome/analyze_memory/__init__.py
@@ -793,8 +793,11 @@ class MemoryAnalyzer:
         """Scan ESPHome source object files to map extern "C" symbols to components.
 
         When no linker map file is available, this uses ``nm`` to scan ``.o`` files
-        under ``src/esphome/`` and build a symbol-to-component mapping. This catches
-        ``extern "C"`` functions and other symbols that lack C++ namespace prefixes.
+        under ``src/`` (including ``src/main.cpp.o`` and everything beneath
+        ``src/esphome/``) and build a symbol-to-component mapping. This catches
+        ``extern "C"`` functions, the ESPHome-generated ``setup()``/``loop()``
+        entry points in ``main.cpp``, and other symbols that lack C++ namespace
+        prefixes.
 
         Skips scanning if ``_source_symbol_map`` was already populated by
         ``_parse_map_file()``.
@@ -806,12 +809,12 @@ class MemoryAnalyzer:
         if obj_dir is None:
             return
 
-        # Find ESPHome source object files
-        esphome_src_dir = obj_dir / "src" / "esphome"
-        if not esphome_src_dir.is_dir():
+        # Scan all ESPHome-owned source object files: src/main.cpp.o and src/esphome/...
+        src_dir = obj_dir / "src"
+        if not src_dir.is_dir():
             return
 
-        obj_files = sorted(esphome_src_dir.rglob("*.o"))
+        obj_files = sorted(src_dir.rglob("*.o"))
         if not obj_files:
             return
 
@@ -1064,6 +1067,10 @@ class MemoryAnalyzer:
                 if component_name in self.external_components:
                     return f"{_COMPONENT_PREFIX_EXTERNAL}{component_name}"
 
+        # ESPHome-generated entry point: src/main.cpp.o (contains setup()/loop())
+        if len(parts) >= 2 and parts[-2:] == ("src", "main.cpp.o"):
+            return _COMPONENT_CORE
+
         # ESPHome core: src/esphome/core/... or src/esphome/...
         if "core" in parts and "esphome" in parts:
             return _COMPONENT_CORE
diff --git a/tests/unit_tests/analyze_memory/test_source_file_attribution.py b/tests/unit_tests/analyze_memory/test_source_file_attribution.py
new file mode 100644
index 00000000000..2793f41bd0e
--- /dev/null
+++ b/tests/unit_tests/analyze_memory/test_source_file_attribution.py
@@ -0,0 +1,43 @@
+"""Tests for source-file-to-component attribution in memory analyzer."""
+
+from unittest.mock import patch
+
+from esphome.analyze_memory import MemoryAnalyzer
+
+
+def _make_analyzer(external_components: set[str] | None = None) -> MemoryAnalyzer:
+    """Create a MemoryAnalyzer with mocked dependencies."""
+    with patch.object(MemoryAnalyzer, "__init__", lambda self, *a, **kw: None):
+        analyzer = MemoryAnalyzer.__new__(MemoryAnalyzer)
+        analyzer.external_components = external_components or set()
+        analyzer._lib_hash_to_name = {}
+    return analyzer
+
+
+def test_source_file_to_component_main_cpp_relative() -> None:
+    """ESPHome-generated src/main.cpp.o (nm path form) attributes to core."""
+    analyzer = _make_analyzer()
+    assert analyzer._source_file_to_component("src/main.cpp.o") == "[esphome]core"
+
+
+def test_source_file_to_component_main_cpp_pioenvs_path() -> None:
+    """Linker map paths like .pioenvs/<env>/src/main.cpp.o attribute to core."""
+    analyzer = _make_analyzer()
+    result = analyzer._source_file_to_component(".pioenvs/drivewaygate/src/main.cpp.o")
+    assert result == "[esphome]core"
+
+
+def test_source_file_to_component_esphome_core() -> None:
+    """Sources under src/esphome/core/ attribute to core."""
+    analyzer = _make_analyzer()
+    result = analyzer._source_file_to_component("src/esphome/core/application.cpp.o")
+    assert result == "[esphome]core"
+
+
+def test_source_file_to_component_known_component() -> None:
+    """Known ESPHome components attribute to their component name."""
+    analyzer = _make_analyzer()
+    result = analyzer._source_file_to_component(
+        "src/esphome/components/wifi/wifi_component.cpp.o"
+    )
+    assert result == "[esphome]wifi"