diff --git a/backend-spring/src/main/java/com/erp/controller/SubstituteController.java b/backend-spring/src/main/java/com/erp/controller/SubstituteController.java
index e0ef5e32..5f5d8844 100644
--- a/backend-spring/src/main/java/com/erp/controller/SubstituteController.java
+++ b/backend-spring/src/main/java/com/erp/controller/SubstituteController.java
@@ -53,7 +53,7 @@ public class SubstituteController {
             @PathVariable("id") Long substituteId,
             @RequestAttribute("company_code") String companyCode,
             @RequestAttribute("role") String role) {
-        if (!"ADMIN".equals(role) && !"SUPER_ADMIN".equals(role)) {
+        if (!"ADMIN".equals(role) && !"COMPANY_ADMIN".equals(role) && !"SUPER_ADMIN".equals(role)) {
             return ResponseEntity.status(HttpStatus.FORBIDDEN)
                     .body(ApiResponse.error("관리자만 조회할 수 있습니다."));
         }
diff --git a/backend-spring/src/main/java/com/erp/service/SubstituteService.java b/backend-spring/src/main/java/com/erp/service/SubstituteService.java
index 6e69e81a..91dd408f 100644
--- a/backend-spring/src/main/java/com/erp/service/SubstituteService.java
+++ b/backend-spring/src/main/java/com/erp/service/SubstituteService.java
@@ -239,7 +239,7 @@ public class SubstituteService extends BaseService {
 
     private void requireAdmin(Map<String, Object> params) {
         String role = (String) params.get("role");
-        if (!"ADMIN".equals(role) && !"SUPER_ADMIN".equals(role)) {
+        if (!"ADMIN".equals(role) && !"COMPANY_ADMIN".equals(role) && !"SUPER_ADMIN".equals(role)) {
             throw new AccessDeniedException("관리자만 대무자를 지정/수정/해지할 수 있습니다.");
         }
     }
diff --git a/backend-spring/src/main/resources/mapper/approval.xml b/backend-spring/src/main/resources/mapper/approval.xml
index 91005bb9..aad08c1e 100644
--- a/backend-spring/src/main/resources/mapper/approval.xml
+++ b/backend-spring/src/main/resources/mapper/approval.xml
@@ -222,7 +222,7 @@
           AND L.COMPANY_CODE = R.COMPANY_CODE
       )
     </if>
-    ORDER BY R.CREATED_DATE DESC
+    ORDER BY R.CREATED_AT DESC
     <if test="page_limit != null">
       LIMIT #{page_limit} OFFSET #{page_offset}
     </if>
@@ -465,7 +465,7 @@
     SELECT L.*,
            R.TITLE, R.TARGET_TABLE, R.TARGET_RECORD_ID,
            R.REQUESTER_NAME, R.REQUESTER_DEPT,
-           R.CREATED_DATE AS REQUEST_CREATED_DATE
+           R.CREATED_AT AS REQUEST_CREATED_DATE
     FROM APPROVAL_LINES L
     JOIN APPROVAL_REQUESTS R
       ON L.REQUEST_ID = R.REQUEST_ID AND L.COMPANY_CODE = R.COMPANY_CODE
@@ -475,7 +475,7 @@
       </foreach>
       AND L.STATUS = 'pending'
       AND (L.COMPANY_CODE = #{company_code} OR L.COMPANY_CODE = '*')
-    ORDER BY R.CREATED_DATE ASC
+    ORDER BY R.CREATED_AT ASC
   </select>
 
   <!-- ================================================================
diff --git a/frontend/components/admin/SubstituteSection.tsx b/frontend/components/admin/SubstituteSection.tsx
index 3f02f108..adae87b5 100644
--- a/frontend/components/admin/SubstituteSection.tsx
+++ b/frontend/components/admin/SubstituteSection.tsx
@@ -6,12 +6,20 @@ import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
 import { Textarea } from "@/components/ui/textarea";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
 import {
   getSubstituteList,
   createSubstitute,
   deleteSubstitute,
   checkSubstituteOverlap,
 } from "@/lib/api/substitute";
+import { getUserList } from "@/lib/api/user";
 
 /**
  * 사용자별 대무자(代務者) 관리 섹션.
@@ -39,6 +47,10 @@ export function SubstituteSection({ originalUserId, originalUserName }: Substitu
   const [dialogOpen, setDialogOpen] = useState(false);
   const [submitting, setSubmitting] = useState(false);
 
+  // 같은 회사 활성 사용자 목록 (대무자 후보) — 본인/SUPER_ADMIN/비활성 제외
+  const [candidates, setCandidates] = useState<Record<string, any>[]>([]);
+  const [candidatesLoading, setCandidatesLoading] = useState(false);
+
   const [form, setForm] = useState({
     proxy_user_id: "",
     start_date: "",
@@ -63,10 +75,29 @@ export function SubstituteSection({ originalUserId, originalUserName }: Substitu
     load();
   }, [load]);
 
+  // 대무자 후보 사용자 목록 로드 (다이얼로그 열릴 때 한번)
+  const loadCandidates = useCallback(async () => {
+    setCandidatesLoading(true);
+    const res = await getUserList({ status: "active", limit: 1000 });
+    if (res?.success && Array.isArray(res.data?.list)) {
+      const filtered = (res.data.list as Record<string, any>[]).filter(
+        (u) =>
+          u.user_id !== originalUserId &&
+          u.user_type !== "SUPER_ADMIN" &&
+          u.status === "active",
+      );
+      setCandidates(filtered);
+    } else {
+      setCandidates([]);
+    }
+    setCandidatesLoading(false);
+  }, [originalUserId]);
+
   const openDialog = () => {
     setForm({ proxy_user_id: "", start_date: "", end_date: "", reason: "" });
     setError(null);
     setDialogOpen(true);
+    loadCandidates();
   };
 
   const submit = async () => {
@@ -215,16 +246,36 @@ export function SubstituteSection({ originalUserId, originalUserName }: Substitu
 
           <div className="space-y-3 py-2 text-sm">
             <div>
-              <Label htmlFor="proxy_user_id">대무자 사용자 ID</Label>
-              <Input
-                id="proxy_user_id"
+              <Label htmlFor="proxy_user_id">대무자</Label>
+              <Select
                 value={form.proxy_user_id}
-                onChange={(e) => setForm({ ...form, proxy_user_id: e.target.value })}
-                placeholder="예: hjkim"
-                autoFocus
-              />
+                onValueChange={(v) => setForm({ ...form, proxy_user_id: v })}
+              >
+                <SelectTrigger id="proxy_user_id" autoFocus>
+                  <SelectValue
+                    placeholder={
+                      candidatesLoading
+                        ? "사용자 목록 불러오는 중..."
+                        : candidates.length === 0
+                          ? "지정 가능한 사용자가 없습니다"
+                          : "대무자를 선택하세요"
+                    }
+                  />
+                </SelectTrigger>
+                <SelectContent>
+                  {candidates.map((u) => (
+                    <SelectItem key={u.user_id} value={u.user_id}>
+                      {u.user_name || u.user_id}
+                      <span className="ml-1 text-muted-foreground">
+                        ({u.user_id}
+                        {u.dept_name ? ` · ${u.dept_name}` : ""})
+                      </span>
+                    </SelectItem>
+                  ))}
+                </SelectContent>
+              </Select>
               <p className="mt-1 text-[0.7rem] text-muted-foreground">
-                같은 회사 사용자만 지정 가능. SUPER_ADMIN 은 지정 불가.
+                같은 회사 활성 사용자만 표시. 본인·SUPER_ADMIN 자동 제외.
               </p>
             </div>