diff --git a/cyclopts/_convert.py b/cyclopts/_convert.py
index cca2c483..cd73e9d3 100644
--- a/cyclopts/_convert.py
+++ b/cyclopts/_convert.py
@@ -216,7 +216,8 @@ def _convert(
             out = convert_tuple(type_, token, converter=converter)
         else:
             out = convert_tuple(type_, *token, converter=converter)
-    elif origin_type in ITERABLE_TYPES:  # NOT including tuple
+    elif origin_type in ITERABLE_TYPES:
+        # NOT including tuple; handled in ``origin_type is tuple`` body above.
         count, _ = token_count(inner_types[0])
         if not isinstance(token, Sequence):
             raise ValueError
diff --git a/cyclopts/argument.py b/cyclopts/argument.py
index 996ea890..c9ad7985 100644
--- a/cyclopts/argument.py
+++ b/cyclopts/argument.py
@@ -8,6 +8,7 @@
 
 import cyclopts.utils
 from cyclopts._convert import (
+    ITERABLE_TYPES,
     convert,
     token_count,
 )
@@ -112,6 +113,16 @@ def _identity_converter(type_, token):
     return token
 
 
+def _get_parameters(hint: Any) -> tuple[Any, list[Parameter]]:
+    """At root level, checks for cyclopts.Parameter annotations."""
+    if is_annotated(hint):
+        inner = get_args(hint)
+        hint = inner[0]
+        return hint, [x for x in inner[1:] if isinstance(x, Parameter)]
+    else:
+        return hint, []
+
+
 class ArgumentCollection(list["Argument"]):
     """A list-like container for :class:`Argument`."""
 
@@ -206,10 +217,23 @@ def _from_type(
         cyclopts_parameters_no_group = []
 
         hint = field_info.hint
-        if is_annotated(hint):
-            annotations = hint.__metadata__  # pyright: ignore
-            hint = get_args(hint)[0]
-            cyclopts_parameters_no_group.extend(x for x in annotations if isinstance(x, Parameter))
+        hint, hint_parameters = _get_parameters(hint)
+        cyclopts_parameters_no_group.extend(hint_parameters)
+
+        # Handle annotations where ``Annotated`` is not at the root level; e.g. ``list[Annotated[...]]``.
+        # Multiple inner Parameter Annotations only make sense if providing specific converter/validators.
+        origin = get_origin(hint)
+        if origin is tuple:
+            # handled in _convert.py
+            pass
+        elif origin in ITERABLE_TYPES:
+            inner_hints = get_args(hint)
+            if len(inner_hints) > 1:
+                raise NotImplementedError(f"Did not expect multiple inner type arguments: {inner_hints}.")
+            elif len(inner_hints) == 1:
+                inner_hint = inner_hints[0]
+                _, hint_parameters = _get_parameters(inner_hint)
+                cyclopts_parameters_no_group.extend(hint_parameters)
 
         if not keys:  # root hint annotation
             if field_info.kind is field_info.VAR_KEYWORD:
@@ -245,6 +269,7 @@ def _from_type(
         # if not immediate_parameter.parse:
         #    return out
 
+        # resolve/derive the parameter name
         if keys:
             cparam = Parameter.combine(
                 upstream_parameter,
diff --git a/pyproject.toml b/pyproject.toml
index 8019cd7e..ad10fcc5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -184,6 +184,7 @@ convention = "numpy"
     "D106",
     "D107",
     "D205",
+    "D400",
     "D404",
     "S102",  # use of "exec"
     "S106",  # possible hardcoded password.
diff --git a/tests/types/test_types_number.py b/tests/types/test_types_number.py
index 3c8c3bda..09457540 100644
--- a/tests/types/test_types_number.py
+++ b/tests/types/test_types_number.py
@@ -1,3 +1,5 @@
+from typing import Optional
+
 import pytest
 
 from cyclopts.exceptions import ValidationError
@@ -18,3 +20,23 @@ def default(color: tuple[UInt8, UInt8, UInt8] = (0x00, 0x00, 0x00)):
     with pytest.raises(ValidationError) as e:
         app.parse_args("--color 100 200 300", exit_on_error=False)
     assert str(e.value) == 'Invalid value "300" for "--color". Must be <= 255.'
+
+
+def test_nested_list_annotated_validator(app, assert_parse_args):
+    @app.default
+    def default(color: Optional[list[tuple[UInt8, UInt8, UInt8]]] = None):
+        pass
+
+    assert_parse_args(
+        default,
+        "0x12 0x34 0x56 0x78 0x90 0xAB",
+        [(0x12, 0x34, 0x56), (0x78, 0x90, 0xAB)],
+    )
+
+    with pytest.raises(ValidationError) as e:
+        app.parse_args("100 200 300", exit_on_error=False)
+    assert str(e.value) == 'Invalid value "300" for "COLOR". Must be <= 255.'
+
+    with pytest.raises(ValidationError) as e:
+        app.parse_args("--color 100 200 300", exit_on_error=False)
+    assert str(e.value) == 'Invalid value "300" for "--color". Must be <= 255.'
diff --git a/tests/types/test_types_path.py b/tests/types/test_types_path.py
index 6ac34e77..a75f8340 100644
--- a/tests/types/test_types_path.py
+++ b/tests/types/test_types_path.py
@@ -28,6 +28,28 @@ def test_types_existing_file(convert, tmp_file):
     assert tmp_file == convert(ct.ExistingFile, tmp_file)
 
 
+def test_types_existing_file_app(app):
+    """https://github.com/BrianPugh/cyclopts/issues/287"""
+
+    @app.default
+    def main(f: ct.ExistingFile):
+        pass
+
+    with pytest.raises(ValidationError):
+        app(["this-file-does-not-exist"], exit_on_error=False)
+
+
+def test_types_existing_file_app_list(app):
+    """https://github.com/BrianPugh/cyclopts/issues/287"""
+
+    @app.default
+    def main(f: list[ct.ExistingFile]):
+        pass
+
+    with pytest.raises(ValidationError):
+        app(["this-file-does-not-exist"], exit_on_error=False)
+
+
 def test_types_existing_file_validation_error(convert, tmp_path):
     with pytest.raises(ValidationError):
         convert(ct.ExistingFile, tmp_path)