diff --git a/bitnet_tools/geo.py b/bitnet_tools/geo.py
new file mode 100644
index 0000000..125e77a
--- /dev/null
+++ b/bitnet_tools/geo.py
@@ -0,0 +1,82 @@
+from __future__ import annotations
+
+import math
+from typing import Any
+
+
+MISSING_OR_NON_NUMERIC = 'missing_or_non_numeric'
+OUT_OF_RANGE = 'out_of_range'
+DISTANCE_THRESHOLD_EXCEEDED = 'distance_threshold_exceeded'
+
+
+def _coerce_float(value: Any) -> float | None:
+    if value is None:
+        return None
+    if isinstance(value, str) and not value.strip():
+        return None
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return None
+
+
+def validate_lat_lon(lat: Any, lon: Any) -> bool:
+    lat_f = _coerce_float(lat)
+    lon_f = _coerce_float(lon)
+    if lat_f is None or lon_f is None:
+        return False
+    return -90.0 <= lat_f <= 90.0 and -180.0 <= lon_f <= 180.0
+
+
+def haversine_km(lat1: float, lon1: float, lat2: float, lon2: float) -> float:
+    radius_km = 6371.0
+    lat1_rad = math.radians(lat1)
+    lon1_rad = math.radians(lon1)
+    lat2_rad = math.radians(lat2)
+    lon2_rad = math.radians(lon2)
+
+    dlat = lat2_rad - lat1_rad
+    dlon = lon2_rad - lon1_rad
+    a = (
+        math.sin(dlat / 2) ** 2
+        + math.cos(lat1_rad) * math.cos(lat2_rad) * math.sin(dlon / 2) ** 2
+    )
+    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+    return radius_km * c
+
+
+def flag_geo_suspects(
+    rows: list[dict[str, Any]],
+    lat_col: str,
+    lon_col: str,
+    threshold_km: float = 25,
+) -> list[dict[str, Any]]:
+    flagged: list[dict[str, Any]] = []
+    prev_valid_coord: tuple[float, float] | None = None
+
+    for row in rows:
+        out = dict(row)
+        reasons: list[str] = []
+        lat_raw = row.get(lat_col)
+        lon_raw = row.get(lon_col)
+        lat = _coerce_float(lat_raw)
+        lon = _coerce_float(lon_raw)
+        distance_km: float | None = None
+
+        if lat is None or lon is None:
+            reasons.append(MISSING_OR_NON_NUMERIC)
+        elif not validate_lat_lon(lat, lon):
+            reasons.append(OUT_OF_RANGE)
+        else:
+            if prev_valid_coord is not None:
+                distance_km = haversine_km(prev_valid_coord[0], prev_valid_coord[1], lat, lon)
+                if distance_km >= float(threshold_km):
+                    reasons.append(DISTANCE_THRESHOLD_EXCEEDED)
+            prev_valid_coord = (lat, lon)
+
+        out['is_suspect'] = bool(reasons)
+        out['suspect_reason'] = '|'.join(reasons)
+        out['distance_km'] = round(distance_km, 3) if distance_km is not None else None
+        flagged.append(out)
+
+    return flagged
diff --git a/bitnet_tools/ui/app.js b/bitnet_tools/ui/app.js
index c367aee..0bd97ce 100644
--- a/bitnet_tools/ui/app.js
+++ b/bitnet_tools/ui/app.js
@@ -45,6 +45,11 @@ const UI = {
   filterType: document.getElementById('filterType'),
   insightList: document.getElementById('insightList'),
   insightDrilldown: document.getElementById('insightDrilldown'),
+  geoLatCol: document.getElementById('geoLatCol'),
+  geoLonCol: document.getElementById('geoLonCol'),
+  geoThreshold: document.getElementById('geoThreshold'),
+  geoExtractBtn: document.getElementById('geoExtractBtn'),
+  geoResult: document.getElementById('geoResult'),
 };
 
 const STATUS = {
@@ -360,6 +365,7 @@ function toggleBusy(isBusy) {
     UI.retryChartsJobBtn,
     UI.switchToCsvBtn,
     UI.candidateTableSelect,
+    UI.geoExtractBtn,
     ...document.querySelectorAll('.mode-btn'),
     ...document.querySelectorAll('.chip'),
   ];
@@ -955,6 +961,85 @@ async function runByIntent() {
   setStatus('의도 라우팅 실패');
 }
 
+
+
+function renderGeoResult(data) {
+  if (!UI.geoResult) return;
+  const artifactLinks = Object.entries(data?.artifacts || {})
+    .map(([key, value]) => `${key}: ${value}`)
+    .join('\n');
+  UI.geoResult.textContent = [
+    `총 ${data?.count ?? 0}건 / 의심 ${data?.suspect_count ?? 0}건 / 정상 ${data?.normal_count ?? 0}건`,
+    `threshold_km=${data?.threshold_km ?? 25}`,
+    artifactLinks,
+  ].filter(Boolean).join('\n');
+}
+
+async function runGeoSuspectExtract() {
+  const file = UI.csvFile?.files?.[0] || null;
+  const latCol = String(UI.geoLatCol?.value || '').trim();
+  const lonCol = String(UI.geoLonCol?.value || '').trim();
+  const threshold = Number(UI.geoThreshold?.value || 25);
+
+  if (!latCol || !lonCol) {
+    showError('위도/경도 컬럼명을 입력하세요.', 'geoLatCol/geoLonCol is empty');
+    return;
+  }
+
+  let payload;
+  if (file) {
+    const inputType = getInputTypeForFile(file);
+    if (inputType === 'excel') {
+      payload = {
+        input_type: 'excel',
+        source_name: file.name,
+        file_base64: await readFileAsBase64(file),
+        sheet_name: UI.sheetSelect?.value || '',
+      };
+    } else if (inputType === 'document') {
+      payload = {
+        input_type: 'document',
+        source_name: file.name,
+        file_base64: await readFileAsBase64(file),
+        table_index: Number(UI.sheetSelect?.value || 0),
+      };
+    } else {
+      payload = {
+        input_type: 'csv',
+        source_name: file.name,
+        normalized_csv_text: await file.text(),
+      };
+    }
+  } else {
+    payload = {
+      input_type: 'csv',
+      source_name: '<inline_csv>',
+      normalized_csv_text: UI.csvText?.value || '',
+    };
+  }
+
+  clearError();
+  try {
+    toggleBusy(true);
+    setStatus('Geo 의심 케이스 추출 중...');
+    const data = await postJson('/api/geo/suspects', {
+      ...payload,
+      lat_col: latCol,
+      lon_col: lonCol,
+      threshold_km: Number.isFinite(threshold) ? threshold : 25,
+      inline: false,
+      include_geojson: false,
+    }, 'Geo 의심 케이스 추출');
+    renderGeoResult(data);
+    setStatus('Geo 의심 케이스 추출 완료');
+  } catch (err) {
+    showError(err.userMessage || 'Geo 의심 케이스 추출 실패', err.detail || '');
+    setStatus('Geo 의심 케이스 추출 실패');
+  } finally {
+    toggleBusy(false);
+  }
+}
+
 function bindEvents() {
   document.querySelectorAll('.mode-btn').forEach((btn) => {
     btn.addEventListener('click', () => setMode(btn.dataset.mode));
@@ -1019,6 +1104,7 @@ function bindEvents() {
   UI.runBtn?.addEventListener('click', runModel);
   UI.multiAnalyzeBtn?.addEventListener('click', runMultiAnalyze);
   UI.startChartsJobBtn?.addEventListener('click', startChartsJob);
+  UI.geoExtractBtn?.addEventListener('click', runGeoSuspectExtract);
   UI.retryChartsJobBtn?.addEventListener('click', retryChartsJob);
   UI.retryPreprocessBtn?.addEventListener('click', async () => {
     if (!appState.preprocessJob.payload) {
diff --git a/bitnet_tools/ui/index.html b/bitnet_tools/ui/index.html
index 7ed2212..dce571f 100644
--- a/bitnet_tools/ui/index.html
+++ b/bitnet_tools/ui/index.html
@@ -83,6 +83,30 @@ <h2>3) 실행 상태</h2>
         </details>
       </section>
 
+
+      <section class="panel">
+        <h2>Geo 의심 케이스 추출</h2>
+        <p class="sub">지도 렌더링 없이 의심 케이스 파일(CSV/JSON)을 생성합니다.</p>
+        <div class="row">
+          <div>
+            <label>위도 컬럼명</label>
+            <input id="geoLatCol" placeholder="예: lat" />
+          </div>
+          <div>
+            <label>경도 컬럼명</label>
+            <input id="geoLonCol" placeholder="예: lon" />
+          </div>
+          <div>
+            <label>거리 임계값(km)</label>
+            <input id="geoThreshold" type="number" min="0" step="0.1" value="25" />
+          </div>
+        </div>
+        <div class="actions">
+          <button id="geoExtractBtn" type="button">의심 케이스 추출 다운로드</button>
+        </div>
+        <pre id="geoResult" aria-live="polite">Geo 추출 대기 중</pre>
+      </section>
+
       <section class="panel">
         <h2>4) 결과</h2>
         <div id="analyzeAssist" class="analyze-assist" aria-live="polite" hidden>
diff --git a/bitnet_tools/web.py b/bitnet_tools/web.py
index c831904..b4eca9f 100644
--- a/bitnet_tools/web.py
+++ b/bitnet_tools/web.py
@@ -22,6 +22,7 @@
 
 from .analysis import build_analysis_payload_from_request
 from .document_extract import extract_document_tables_from_base64, table_to_analysis_request
+from .geo import flag_geo_suspects, validate_lat_lon
 from .multi_csv import analyze_multiple_csv
 from .planner import build_plan, execute_plan_from_csv_text, parse_question_to_intent
 from .visualize import create_multi_charts
@@ -215,6 +216,65 @@ def _classify_preprocess_error(exc: Exception) -> str:
     return 'parser_error'
 
 
+def _rows_from_csv_text(csv_text: str) -> tuple[list[str], list[dict[str, Any]]]:
+    reader = csv.DictReader(io.StringIO(csv_text))
+    fieldnames = [str(name) for name in (reader.fieldnames or []) if name is not None]
+    if not fieldnames:
+        raise ValueError('csv header is required')
+    rows = [dict(row) for row in reader]
+    return fieldnames, rows
+
+
+def _build_geojson_feature_collection(rows: list[dict[str, Any]], lat_col: str, lon_col: str) -> dict[str, Any]:
+    features: list[dict[str, Any]] = []
+    for row in rows:
+        if not validate_lat_lon(row.get(lat_col), row.get(lon_col)):
+            continue
+        lon = float(row[lon_col])
+        lat = float(row[lat_col])
+        feature_props = {k: v for k, v in row.items() if k not in {lat_col, lon_col}}
+        features.append({
+            'type': 'Feature',
+            'geometry': {'type': 'Point', 'coordinates': [lon, lat]},
+            'properties': feature_props,
+        })
+    return {'type': 'FeatureCollection', 'features': features}
+
+
+def _write_geo_suspect_artifacts(
+    result_rows: list[dict[str, Any]],
+    fieldnames: list[str],
+    lat_col: str,
+    lon_col: str,
+    include_geojson: bool,
+) -> dict[str, str]:
+    out_dir = Path('.bitnet_cache') / 'geo_suspects' / uuid.uuid4().hex
+    out_dir.mkdir(parents=True, exist_ok=True)
+
+    csv_path = out_dir / 'geo_suspects.csv'
+    json_path = out_dir / 'geo_suspects.json'
+    geojson_path = out_dir / 'geo_suspects.geojson'
+
+    ordered_fields = list(fieldnames)
+    for col in ['is_suspect', 'suspect_reason', 'distance_km']:
+        if col not in ordered_fields:
+            ordered_fields.append(col)
+
+    with csv_path.open('w', encoding='utf-8', newline='') as f:
+        writer = csv.DictWriter(f, fieldnames=ordered_fields)
+        writer.writeheader()
+        writer.writerows(result_rows)
+
+    json_path.write_text(json.dumps(result_rows, ensure_ascii=False, indent=2), encoding='utf-8')
+
+    artifacts = {'csv': str(csv_path), 'json': str(json_path)}
+    if include_geojson:
+        geojson = _build_geojson_feature_collection(result_rows, lat_col, lon_col)
+        geojson_path.write_text(json.dumps(geojson, ensure_ascii=False, indent=2), encoding='utf-8')
+        artifacts['geojson'] = str(geojson_path)
+    return artifacts
+
+
 def _cleanup_expired_preprocess_jobs() -> None:
     now = datetime.now(timezone.utc)
     threshold = now - timedelta(seconds=PREPROCESS_JOB_TTL_SECONDS)
@@ -562,6 +622,56 @@ def do_POST(self) -> None:
                 return self._send_json({'job_id': job_id, 'status': 'queued'}, HTTPStatus.ACCEPTED)
 
 
+
+            if route == '/api/geo/suspects':
+                lat_col = str(payload.get('lat_col', '')).strip()
+                lon_col = str(payload.get('lon_col', '')).strip()
+                threshold_km = float(payload.get('threshold_km', 25) or 25)
+                include_geojson = bool(payload.get('include_geojson', False))
+                inline = bool(payload.get('inline', True))
+
+                if not lat_col or not lon_col:
+                    return self._send_json(self._error_payload('lat_col and lon_col are required'), HTTPStatus.BAD_REQUEST)
+
+                file_payload = {
+                    'input_type': str(payload.get('input_type', 'csv') or 'csv'),
+                    'name': str(payload.get('source_name', '<inline_csv>') or '<inline_csv>'),
+                    'normalized_csv_text': str(payload.get('normalized_csv_text', '') or ''),
+                    'csv_text': str(payload.get('csv_text', '') or ''),
+                    'file_base64': payload.get('file_base64', ''),
+                    'sheet_name': payload.get('sheet_name', ''),
+                    'table_index': payload.get('table_index', 0),
+                }
+                _, normalized_csv_text, _ = _coerce_csv_text_from_file_payload(file_payload)
+                fieldnames, rows = _rows_from_csv_text(normalized_csv_text)
+
+                if lat_col not in fieldnames or lon_col not in fieldnames:
+                    return self._send_json(
+                        self._error_payload('lat_col/lon_col not found in csv header', f'header={fieldnames}'),
+                        HTTPStatus.BAD_REQUEST,
+                    )
+
+                result_rows = flag_geo_suspects(rows, lat_col=lat_col, lon_col=lon_col, threshold_km=threshold_km)
+                suspect_count = sum(1 for row in result_rows if row.get('is_suspect'))
+                normal_count = len(result_rows) - suspect_count
+                artifacts = _write_geo_suspect_artifacts(
+                    result_rows,
+                    fieldnames,
+                    lat_col=lat_col,
+                    lon_col=lon_col,
+                    include_geojson=include_geojson,
+                )
+                response = {
+                    'count': len(result_rows),
+                    'suspect_count': suspect_count,
+                    'normal_count': normal_count,
+                    'threshold_km': threshold_km,
+                    'artifacts': artifacts,
+                }
+                if inline:
+                    response['rows'] = result_rows
+                return self._send_json(response)
+
             if route == "/api/multi-analyze":
                 files = payload.get("files", [])
                 question = str(payload.get("question", "")).strip() or "다중 CSV를 비교 분석해줘"
diff --git a/tests/test_geo.py b/tests/test_geo.py
new file mode 100644
index 0000000..4fb7b38
--- /dev/null
+++ b/tests/test_geo.py
@@ -0,0 +1,60 @@
+from bitnet_tools.geo import (
+    DISTANCE_THRESHOLD_EXCEEDED,
+    MISSING_OR_NON_NUMERIC,
+    OUT_OF_RANGE,
+    flag_geo_suspects,
+    haversine_km,
+    validate_lat_lon,
+)
+
+
+def test_validate_lat_lon_range_checks():
+    assert validate_lat_lon(37.5, 127.0) is True
+    assert validate_lat_lon(-90, -180) is True
+    assert validate_lat_lon(90, 180) is True
+    assert validate_lat_lon(91, 127) is False
+    assert validate_lat_lon(37, -181) is False
+
+
+def test_haversine_km_returns_expected_scale():
+    d = haversine_km(37.5665, 126.9780, 35.1796, 129.0756)
+    assert 320 <= d <= 340
+
+
+def test_flag_geo_suspects_distinguishes_missing_range_and_distance():
+    rows = [
+        {'id': '1', 'lat': '37.5665', 'lon': '126.9780'},
+        {'id': '2', 'lat': '35.1796', 'lon': '129.0756'},
+        {'id': '3', 'lat': '91', 'lon': '127'},
+        {'id': '4', 'lat': '', 'lon': '127.1'},
+    ]
+
+    result = flag_geo_suspects(rows, lat_col='lat', lon_col='lon', threshold_km=25)
+
+    assert result[0]['is_suspect'] is False
+    assert result[0]['suspect_reason'] == ''
+    assert result[0]['distance_km'] is None
+
+    assert result[1]['is_suspect'] is True
+    assert result[1]['suspect_reason'] == DISTANCE_THRESHOLD_EXCEEDED
+    assert result[1]['distance_km'] is not None
+    assert result[1]['distance_km'] >= 25
+
+    assert result[2]['is_suspect'] is True
+    assert result[2]['suspect_reason'] == OUT_OF_RANGE
+    assert result[2]['distance_km'] is None
+
+    assert result[3]['is_suspect'] is True
+    assert result[3]['suspect_reason'] == MISSING_OR_NON_NUMERIC
+    assert result[3]['distance_km'] is None
+
+
+def test_flag_geo_suspects_threshold_boundary_is_inclusive():
+    rows = [
+        {'lat': 0.0, 'lon': 0.0},
+        {'lat': 0.0, 'lon': 1.0},
+    ]
+    # 대략 111km
+    result = flag_geo_suspects(rows, lat_col='lat', lon_col='lon', threshold_km=111)
+    assert result[1]['is_suspect'] is True
+    assert result[1]['suspect_reason'] == DISTANCE_THRESHOLD_EXCEEDED
diff --git a/tests/test_web.py b/tests/test_web.py
index 5b1903a..dc8a9ca 100644
--- a/tests/test_web.py
+++ b/tests/test_web.py
@@ -302,3 +302,44 @@ def test_analyze_api_with_planner_returns_execution_payload():
     finally:
         server.shutdown()
         thread.join(timeout=1)
+
+
+def test_geo_suspects_api_returns_inline_rows_and_artifacts():
+    server, thread = _run_server()
+    base = f'http://127.0.0.1:{server.server_port}'
+    try:
+        code, body = _post_json(base + '/api/geo/suspects', {
+            'input_type': 'csv',
+            'normalized_csv_text': 'id,lat,lon\n1,37.5665,126.978\n2,35.1796,129.0756\n3,,127\n',
+            'lat_col': 'lat',
+            'lon_col': 'lon',
+            'threshold_km': 25,
+            'inline': True,
+            'include_geojson': False,
+        })
+        assert code == 200
+        assert body['count'] == 3
+        assert body['suspect_count'] == 2
+        assert body['normal_count'] == 1
+        assert 'rows' in body
+        assert {'csv', 'json'}.issubset(set(body['artifacts'].keys()))
+    finally:
+        server.shutdown()
+        thread.join(timeout=1)
+
+
+def test_geo_suspects_api_validates_lat_lon_columns():
+    server, thread = _run_server()
+    base = f'http://127.0.0.1:{server.server_port}'
+    try:
+        code, body = _post_json(base + '/api/geo/suspects', {
+            'input_type': 'csv',
+            'normalized_csv_text': 'id,a,b\n1,1,2\n',
+            'lat_col': 'lat',
+            'lon_col': 'lon',
+        })
+        assert code == 400
+        assert body['error'] == 'lat_col/lon_col not found in csv header'
+    finally:
+        server.shutdown()
+        thread.join(timeout=1)