diff --git a/package.json b/package.json
index c19769c..71381bc 100644
--- a/package.json
+++ b/package.json
@@ -33,6 +33,7 @@
     "react-dom": "^19.0.0",
     "react-mobile-picker": "^1.1.2",
     "react-qr-code": "^2.0.15",
+    "yup": "^1.6.1",
     "zustand": "^5.0.3"
   },
   "devDependencies": {
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 7ab76d0..dbaff68 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -50,6 +50,9 @@ importers:
       react-qr-code:
         specifier: ^2.0.15
         version: 2.0.15(react@19.1.0)
+      yup:
+        specifier: ^1.6.1
+        version: 1.6.1
       zustand:
         specifier: ^5.0.3
         version: 5.0.4(@types/react@19.1.4)(react@19.1.0)
@@ -3896,6 +3899,9 @@ packages:
   prop-types@15.8.1:
     resolution: {integrity: sha512-oj87CgZICdulUohogVAR7AjlC0327U4el4L6eAvOqCeudMDVU0NThNaV+b9Df4dXgSP1gXMTnPdhfe/2qDH5cg==}
 
+  property-expr@2.0.6:
+    resolution: {integrity: sha512-SVtmxhRE/CGkn3eZY1T6pC8Nln6Fr/lu1mKSgRud0eC73whjGfoAogbn78LkD8aFL0zz3bAFerKSnOl7NlErBA==}
+
   proto-list@1.2.4:
     resolution: {integrity: sha512-vtK/94akxsTMhe0/cbfpR+syPuszcuwhqVjJq26CuNDgFGj682oRBXOP5MJpv2r7JtE8MsiepGIqvvOTBwn2vA==}
 
@@ -4357,6 +4363,9 @@ packages:
     resolution: {integrity: sha512-pFYqmTw68LXVjeWJMST4+borgQP2AyMNbg1BpZh9LbyhUeNkeaPF9gzfPGUAnSMV3qPYdWUwDIjjCLiSDOl7vg==}
     engines: {node: '>=18'}
 
+  tiny-case@1.0.3:
+    resolution: {integrity: sha512-Eet/eeMhkO6TX8mnUteS9zgPbUMQa4I6Kkp5ORiBD5476/m+PIRiumP5tmh5ioJpH7k51Kehawy2UDfsnxxY8Q==}
+
   tiny-invariant@1.3.3:
     resolution: {integrity: sha512-+FbBPE1o9QAYvviau/qC5SE3caw21q3xkvWKBtja5vgqOWIHHJ3ioaq1VPfn/Szqctz2bU/oYeKd9/z5BL+PVg==}
 
@@ -4397,6 +4406,9 @@ packages:
     resolution: {integrity: sha512-65P7iz6X5yEr1cwcgvQxbbIw7Uk3gOy5dIdtZ4rDveLqhrdJP+Li/Hx6tyK0NEb+2GCyneCMJiGqrADCSNk8sQ==}
     engines: {node: '>=8.0'}
 
+  toposort@2.0.2:
+    resolution: {integrity: sha512-0a5EOkAUp8D4moMi2W8ZF8jcga7BgZd91O/yabJCFY8az+XSzeGyTKs0Aoo897iV1Nj6guFq8orWDS96z91oGg==}
+
   totalist@3.0.1:
     resolution: {integrity: sha512-sf4i37nQ2LBx4m3wB74y+ubopq6W/dIzXg0FDGjsYnZHVa1Da8FH853wlL2gtUhg+xJXjfk3kUZS3BRoQeoQBQ==}
     engines: {node: '>=6'}
@@ -4713,6 +4725,9 @@ packages:
     resolution: {integrity: sha512-cYVsTjKl8b+FrnidjibDWskAv7UKOfcwaVZdp/it9n1s9fU3IkgDbhdIRKCW4JDsAlECJY0ytoVPT3sK6kideA==}
     engines: {node: '>=18'}
 
+  yup@1.6.1:
+    resolution: {integrity: sha512-JED8pB50qbA4FOkDol0bYF/p60qSEDQqBD0/qeIrUCG1KbPBIQ776fCUNb9ldbPcSTxA69g/47XTo4TqWiuXOA==}
+
   zustand@5.0.4:
     resolution: {integrity: sha512-39VFTN5InDtMd28ZhjLyuTnlytDr9HfwO512Ai4I8ZABCoyAj4F1+sr7sD1jP/+p7k77Iko0Pb5NhgBFDCX0kQ==}
     engines: {node: '>=12.20.0'}
@@ -8730,6 +8745,8 @@ snapshots:
       object-assign: 4.1.1
       react-is: 16.13.1
 
+  property-expr@2.0.6: {}
+
   proto-list@1.2.4: {}
 
   proxy-agent@6.5.0:
@@ -9314,6 +9331,8 @@ snapshots:
       glob: 10.4.5
       minimatch: 9.0.5
 
+  tiny-case@1.0.3: {}
+
   tiny-invariant@1.3.3: {}
 
   tiny-warning@1.0.3: {}
@@ -9343,6 +9362,8 @@ snapshots:
     dependencies:
       is-number: 7.0.0
 
+  toposort@2.0.2: {}
+
   totalist@3.0.1: {}
 
   tree-kill@1.2.2: {}
@@ -9703,6 +9724,13 @@ snapshots:
 
   yoctocolors-cjs@2.1.2: {}
 
+  yup@1.6.1:
+    dependencies:
+      property-expr: 2.0.6
+      tiny-case: 1.0.3
+      toposort: 2.0.2
+      type-fest: 2.19.0
+
   zustand@5.0.4(@types/react@19.1.4)(react@19.1.0):
     optionalDependencies:
       '@types/react': 19.1.4
diff --git a/src/app/(auth)/join/[type]/[step]/_components/ParentStep01.tsx b/src/app/(auth)/join/[type]/[step]/_components/ParentStep01.tsx
index 18a172b..c47b801 100644
--- a/src/app/(auth)/join/[type]/[step]/_components/ParentStep01.tsx
+++ b/src/app/(auth)/join/[type]/[step]/_components/ParentStep01.tsx
@@ -14,14 +14,52 @@ const ParentStep01 = () => {
   const router = useRouter()
   const { updateParent } = useUserStore()
   const [nickname, setNickname] = useState("")
+  const [error, setError] = useState("")
+
+  // 닉네임 유효성 검증 함수
+  const validateNickname = (value: string) => {
+    // 빈 값 체크
+    if (!value.trim()) {
+      return "닉네임을 입력해주세요"
+    }
+
+    // 길이 체크
+    if (value.trim().length < 2) {
+      return "닉네임은 최소 2자 이상이어야 합니다"
+    }
+
+    if (value.trim().length > 20) {
+      return "닉네임은 최대 20자까지 입력 가능합니다"
+    }
+
+    // 한글 + 영문 + 숫자 + 언더스코어 + 하이픈만 허용
+    const nicknameRegex = /^[가-힣a-zA-Z0-9_-]+$/
+    if (!nicknameRegex.test(value.trim())) {
+      return "닉네임은 한글, 영문, 숫자, _, - 만 사용 가능합니다"
+    }
+
+    return ""
+  }
 
   const handleChange = (e: React.ChangeEvent<HTMLInputElement>) => {
-    setNickname(e.target.value)
+    const value = e.target.value
+    setNickname(value)
+
+    // 실시간 검증 (선택사항)
+    const validationError = validateNickname(value)
+    setError(validationError)
   }
 
   const handleClickNext = () => {
+    const validationError = validateNickname(nickname)
+
+    if (validationError) {
+      setError(validationError)
+      return
+    }
+
     updateParent({
-      nickname: nickname,
+      nickname: nickname.trim(),
     })
     router.push("/join/parent/2")
   }
@@ -38,6 +76,14 @@ const ParentStep01 = () => {
           placeholder="닉네임 입력"
           onChange={handleChange}
           value={nickname}
+          state={
+            error
+              ? {
+                  type: "error",
+                  message: error,
+                }
+              : null
+          }
         />
       </div>
       <Button
@@ -47,7 +93,7 @@ const ParentStep01 = () => {
         variant="filled"
         classNames={pageStyles.join__content__btn}
         onClick={handleClickNext}
-        aria-disabled={nickname === ""}
+        aria-disabled={!!error}
       />
     </>
   )
diff --git a/src/app/(auth)/join/[type]/[step]/_components/ParentStep02.tsx b/src/app/(auth)/join/[type]/[step]/_components/ParentStep02.tsx
index 8c592b6..9b9fcf3 100644
--- a/src/app/(auth)/join/[type]/[step]/_components/ParentStep02.tsx
+++ b/src/app/(auth)/join/[type]/[step]/_components/ParentStep02.tsx
@@ -3,6 +3,7 @@
 import Picker from "react-mobile-picker"
 
 import { useFormik } from "formik"
+import * as Yup from "yup"
 
 import BoyIcon from "@/assets/character/comm/img-boy.svg"
 import GirlIcon from "@/assets/character/comm/img-girl.svg"
@@ -36,6 +37,27 @@ const ParentStep02 = () => {
   }
   // #endregion
 
+  // #region 유효성 검증
+  const validationSchema = Yup.object({
+    child_name: Yup.string()
+      .required("아이 이름은 필수입니다")
+      .matches(/^[가-힣a-zA-Z\s]+$/, "아이 이름은 한글과 영문만 입력 가능합니다")
+      .min(2, "이름은 최소 2자 이상이어야 합니다")
+      .max(20, "이름은 최대 20자까지 입력 가능합니다"),
+
+    child_gender: Yup.string()
+      .required("성별을 선택해주세요")
+      .oneOf(["MALE", "FEMALE"], "올바른 성별을 선택해주세요"),
+
+    child_age: Yup.number().required("나이를 선택해주세요"),
+
+    child_height: Yup.number().required("키를 선택해주세요"),
+
+    child_weight: Yup.number().required("몸무게를 선택해주세요"),
+  })
+
+  // #endregion
+
   // #region  Formik
   const formik = useFormik({
     initialValues: {
@@ -45,19 +67,7 @@ const ParentStep02 = () => {
       child_height: 120,
       child_weight: 20,
     },
-    validate: (values) => {
-      const errors: Partial<ChildInfoType> = {}
-
-      if (!values.child_name.trim()) {
-        errors.child_name = "아이 이름은 필수입니다"
-      }
-
-      if (!values.child_gender) {
-        errors.child_gender = "성별을 선택해주세요"
-      }
-
-      return errors
-    },
+    validationSchema,
     onSubmit: async (values: ChildInfoType) => {
       const updatedChildInfo = {
         ...values,
@@ -115,7 +125,7 @@ const ParentStep02 = () => {
           onBlur={formik.handleBlur}
           value={formik.values.child_name}
           state={
-            formik.errors.child_name
+            formik.touched.child_name && formik.errors.child_name
               ? {
                   type: "error",
                   message: formik.errors.child_name,
@@ -128,7 +138,7 @@ const ParentStep02 = () => {
         <fieldset className={`input-comm ${formik.errors.child_gender ? "error" : ""}`}>
           <div className="lab-comm">
             <legend>성별</legend>
-            {!!formik.errors.child_gender && (
+            {formik.touched.child_gender && formik.errors.child_gender && (
               <>
                 <ErrorIconSvg />
                 <p className="lab-state">{formik.errors.child_gender}</p>
@@ -171,7 +181,9 @@ const ParentStep02 = () => {
         <div className="input-comm">
           <div className="lab-comm">
             <label htmlFor="childAge">나이</label>
-            {!!formik.errors.child_age && <p className="lab-state">{formik.errors.child_age}</p>}
+            {formik.touched.child_age && formik.errors.child_age && (
+              <p className="lab-state">{formik.errors.child_age}</p>
+            )}
           </div>
           <div className={styles.item_picker}>
             <Picker
@@ -201,7 +213,7 @@ const ParentStep02 = () => {
         <div className="input-comm">
           <div className="lab-comm">
             <label htmlFor="childHeight">키</label>
-            {!!formik.errors.child_height && (
+            {formik.touched.child_height && formik.errors.child_height && (
               <p className="lab-state">{formik.errors.child_height}</p>
             )}
           </div>
@@ -233,7 +245,7 @@ const ParentStep02 = () => {
         <div className="input-comm">
           <div className="lab-comm">
             <label htmlFor="childWeight">몸무게</label>
-            {!!formik.errors.child_weight && (
+            {formik.touched.child_weight && formik.errors.child_weight && (
               <p className="lab-state">{formik.errors.child_weight}</p>
             )}
           </div>
diff --git a/src/types/auth.ts b/src/types/auth.ts
index db8d62e..027d889 100644
--- a/src/types/auth.ts
+++ b/src/types/auth.ts
@@ -8,4 +8,5 @@ export type ChildInfoType = {
   child_height: number
   child_weight: number
 }
+
 export type ParentJoinRequestType = NicknameType & ChildInfoType