diff --git a/superset/mcp_service/chart/chart_utils.py b/superset/mcp_service/chart/chart_utils.py
index 1d507909d91..41190554b3d 100644
--- a/superset/mcp_service/chart/chart_utils.py
+++ b/superset/mcp_service/chart/chart_utils.py
@@ -345,6 +345,27 @@ def _add_adhoc_filters(
         ]
 
 
+def adhoc_filters_to_query_filters(
+    adhoc_filters: list[Dict[str, Any]],
+) -> list[Dict[str, Any]]:
+    """Convert adhoc filter format to QueryObject filter format.
+
+    Adhoc filters use ``{subject, operator, comparator}`` keys while
+    ``QueryContextFactory`` expects ``{col, op, val}`` (QueryObjectFilterClause).
+    """
+    result: list[Dict[str, Any]] = []
+    for f in adhoc_filters:
+        if f.get("expressionType") == "SIMPLE":
+            result.append(
+                {
+                    "col": f.get("subject"),
+                    "op": f.get("operator"),
+                    "val": f.get("comparator"),
+                }
+            )
+    return result
+
+
 def map_table_config(config: TableChartConfig) -> Dict[str, Any]:
     """Map table chart config to form_data with defensive validation."""
     # Early validation to prevent empty charts
diff --git a/superset/mcp_service/chart/preview_utils.py b/superset/mcp_service/chart/preview_utils.py
index 5b930797b06..dcc8642f000 100644
--- a/superset/mcp_service/chart/preview_utils.py
+++ b/superset/mcp_service/chart/preview_utils.py
@@ -81,11 +81,17 @@ def generate_preview_from_form_data(
 
         # Create query context from form data using factory
         from superset.common.query_context_factory import QueryContextFactory
+        from superset.mcp_service.chart.chart_utils import (
+            adhoc_filters_to_query_filters,
+        )
 
         # Build columns list: include x_axis and groupby for XY charts,
         # fall back to form_data "columns" for table charts
         columns = _build_query_columns(form_data)
 
+        query_filters = adhoc_filters_to_query_filters(
+            form_data.get("adhoc_filters", [])
+        )
         factory = QueryContextFactory()
         query_context_obj = factory.create(
             datasource={"id": dataset_id, "type": "table"},
@@ -95,7 +101,7 @@ def generate_preview_from_form_data(
                     "metrics": form_data.get("metrics", []),
                     "orderby": form_data.get("orderby", []),
                     "row_limit": form_data.get("row_limit", 100),
-                    "filters": form_data.get("adhoc_filters", []),
+                    "filters": query_filters,
                     "time_range": form_data.get("time_range", "No filter"),
                 }
             ],
diff --git a/superset/mcp_service/chart/tool/generate_chart.py b/superset/mcp_service/chart/tool/generate_chart.py
index 64f9e03804f..4a439d3bd74 100644
--- a/superset/mcp_service/chart/tool/generate_chart.py
+++ b/superset/mcp_service/chart/tool/generate_chart.py
@@ -81,10 +81,14 @@ def _compile_chart(
         ChartDataQueryFailedError,
     )
     from superset.common.query_context_factory import QueryContextFactory
+    from superset.mcp_service.chart.chart_utils import adhoc_filters_to_query_filters
     from superset.mcp_service.chart.preview_utils import _build_query_columns
 
     try:
         columns = _build_query_columns(form_data)
+        query_filters = adhoc_filters_to_query_filters(
+            form_data.get("adhoc_filters", [])
+        )
         factory = QueryContextFactory()
         query_context = factory.create(
             datasource={"id": dataset_id, "type": "table"},
@@ -94,7 +98,7 @@ def _compile_chart(
                     "metrics": form_data.get("metrics", []),
                     "orderby": form_data.get("orderby", []),
                     "row_limit": 2,
-                    "filters": form_data.get("adhoc_filters", []),
+                    "filters": query_filters,
                     "time_range": form_data.get("time_range", "No filter"),
                 }
             ],
diff --git a/tests/unit_tests/mcp_service/chart/test_chart_utils.py b/tests/unit_tests/mcp_service/chart/test_chart_utils.py
index 480399f5cec..1a247bf1e89 100644
--- a/tests/unit_tests/mcp_service/chart/test_chart_utils.py
+++ b/tests/unit_tests/mcp_service/chart/test_chart_utils.py
@@ -24,6 +24,7 @@ import pytest
 
 from superset.mcp_service.chart.chart_utils import (
     _add_adhoc_filters,
+    adhoc_filters_to_query_filters,
     configure_temporal_handling,
     create_metric_object,
     generate_chart_name,
@@ -1447,3 +1448,56 @@ class TestValidateChartDataset:
         mock_find.side_effect = SQLAlchemyError("db gone")
         url = generate_explore_link(5, {"viz_type": "table"})
         assert "datasource_id=5" in url
+
+
+class TestAdhocFiltersToQueryFilters:
+    """Tests for adhoc_filters_to_query_filters conversion."""
+
+    def test_converts_simple_filters(self) -> None:
+        adhoc = [
+            {
+                "clause": "WHERE",
+                "expressionType": "SIMPLE",
+                "subject": "genre",
+                "operator": "==",
+                "comparator": "Action",
+            }
+        ]
+        result = adhoc_filters_to_query_filters(adhoc)
+        assert result == [{"col": "genre", "op": "==", "val": "Action"}]
+
+    def test_converts_multiple_filters(self) -> None:
+        adhoc = [
+            {
+                "clause": "WHERE",
+                "expressionType": "SIMPLE",
+                "subject": "genre",
+                "operator": "==",
+                "comparator": "Action",
+            },
+            {
+                "clause": "WHERE",
+                "expressionType": "SIMPLE",
+                "subject": "year",
+                "operator": ">=",
+                "comparator": "2010",
+            },
+        ]
+        result = adhoc_filters_to_query_filters(adhoc)
+        assert len(result) == 2
+        assert result[0] == {"col": "genre", "op": "==", "val": "Action"}
+        assert result[1] == {"col": "year", "op": ">=", "val": "2010"}
+
+    def test_empty_list(self) -> None:
+        assert adhoc_filters_to_query_filters([]) == []
+
+    def test_skips_non_simple_expression_types(self) -> None:
+        adhoc = [
+            {
+                "clause": "WHERE",
+                "expressionType": "SQL",
+                "sqlExpression": "col > 5",
+            }
+        ]
+        result = adhoc_filters_to_query_filters(adhoc)
+        assert result == []