diff --git a/packages/core/src/locales.ts b/packages/core/src/locales.ts
index c79b36cb59..21ff0c85ea 100644
--- a/packages/core/src/locales.ts
+++ b/packages/core/src/locales.ts
@@ -3,6 +3,7 @@ import az from "./locales/az.js";
 import cs from "./locales/cs.js";
 import en from "./locales/en.js";
 import es from "./locales/es.js";
+import ru from "./locales/ru.js";
 import tr from "./locales/tr.js";
 import id from "./locales/id.js";
 import it from "./locales/it.js";
@@ -17,4 +18,4 @@ import fr from "./locales/fr.js";
 import ja from "./locales/ja.js";
 import pt from "./locales/pt.js";
 
-export { ar, az, cs, es, en, fi, he, hu, id, it, pt, tr, ja, fr, pl, ua, vi, zhCN };
+export { ar, az, cs, es, en, fi, fr, he, hu, id, it, ja, pl, pt, ru, tr, ua, vi, zhCN };
diff --git a/packages/core/src/locales/ru.ts b/packages/core/src/locales/ru.ts
new file mode 100644
index 0000000000..6f0119db77
--- /dev/null
+++ b/packages/core/src/locales/ru.ts
@@ -0,0 +1,185 @@
+import type { $ZodStringFormats } from "../checks.js";
+import type * as errors from "../errors.js";
+import * as util from "../util.js";
+
+function getRussianPlural(count: number, one: string, few: string, many: string): string {
+  const absCount = Math.abs(count);
+  const lastDigit = absCount % 10;
+  const lastTwoDigits = absCount % 100;
+
+  if (lastTwoDigits >= 11 && lastTwoDigits <= 19) {
+    return many;
+  }
+
+  if (lastDigit === 1) {
+    return one;
+  }
+
+  if (lastDigit >= 2 && lastDigit <= 4) {
+    return few;
+  }
+
+  return many;
+}
+
+interface RussianSizable {
+  unit: {
+    one: string;
+    few: string;
+    many: string;
+  };
+  verb: string;
+}
+
+const Sizable: Record<string, RussianSizable> = {
+  string: {
+    unit: {
+      one: "символ",
+      few: "символа",
+      many: "символов",
+    },
+    verb: "иметь",
+  },
+  file: {
+    unit: {
+      one: "байт",
+      few: "байта",
+      many: "байт",
+    },
+    verb: "иметь",
+  },
+  array: {
+    unit: {
+      one: "элемент",
+      few: "элемента",
+      many: "элементов",
+    },
+    verb: "иметь",
+  },
+  set: {
+    unit: {
+      one: "элемент",
+      few: "элемента",
+      many: "элементов",
+    },
+    verb: "иметь",
+  },
+};
+
+function getSizing(origin: string): RussianSizable | null {
+  return Sizable[origin] ?? null;
+}
+
+export const parsedType = (data: any): string => {
+  const t = typeof data;
+
+  switch (t) {
+    case "number": {
+      return Number.isNaN(data) ? "NaN" : "число";
+    }
+    case "object": {
+      if (Array.isArray(data)) {
+        return "массив";
+      }
+      if (data === null) {
+        return "null";
+      }
+
+      if (Object.getPrototypeOf(data) !== Object.prototype && data.constructor) {
+        return data.constructor.name;
+      }
+    }
+  }
+  return t;
+};
+
+const Nouns: {
+  [k in $ZodStringFormats | (string & {})]?: string;
+} = {
+  regex: "ввод",
+  email: "email адрес",
+  url: "URL",
+  emoji: "эмодзи",
+  uuid: "UUID",
+  uuidv4: "UUIDv4",
+  uuidv6: "UUIDv6",
+  nanoid: "nanoid",
+  guid: "GUID",
+  cuid: "cuid",
+  cuid2: "cuid2",
+  ulid: "ULID",
+  xid: "XID",
+  ksuid: "KSUID",
+  datetime: "ISO дата и время",
+  date: "ISO дата",
+  time: "ISO время",
+  duration: "ISO длительность",
+  ipv4: "IPv4 адрес",
+  ipv6: "IPv6 адрес",
+  cidrv4: "IPv4 диапазон",
+  cidrv6: "IPv6 диапазон",
+  base64: "строка в формате base64",
+  base64url: "строка в формате base64url",
+  json_string: "JSON строка",
+  e164: "номер E.164",
+  jwt: "JWT",
+  template_literal: "ввод",
+};
+
+const error: errors.$ZodErrorMap = (issue) => {
+  switch (issue.code) {
+    case "invalid_type":
+      return `Неверный ввод: ожидалось ${issue.expected}, получено ${parsedType(issue.input)}`;
+    case "invalid_value":
+      if (issue.values.length === 1) return `Неверный ввод: ожидалось ${util.stringifyPrimitive(issue.values[0])}`;
+      return `Неверный вариант: ожидалось одно из ${util.joinValues(issue.values, "|")}`;
+    case "too_big": {
+      const adj = issue.inclusive ? "<=" : "<";
+      const sizing = getSizing(issue.origin);
+      if (sizing) {
+        const maxValue = Number(issue.maximum);
+        const unit = getRussianPlural(maxValue, sizing.unit.one, sizing.unit.few, sizing.unit.many);
+        return `Слишком большое значение: ожидалось, что ${issue.origin ?? "значение"} будет иметь ${adj}${issue.maximum.toString()} ${unit}`;
+      }
+      return `Слишком большое значение: ожидалось, что ${issue.origin ?? "значение"} будет ${adj}${issue.maximum.toString()}`;
+    }
+    case "too_small": {
+      const adj = issue.inclusive ? ">=" : ">";
+      const sizing = getSizing(issue.origin);
+      if (sizing) {
+        const minValue = Number(issue.minimum);
+        const unit = getRussianPlural(minValue, sizing.unit.one, sizing.unit.few, sizing.unit.many);
+        return `Слишком маленькое значение: ожидалось, что ${issue.origin} будет иметь ${adj}${issue.minimum.toString()} ${unit}`;
+      }
+      return `Слишком маленькое значение: ожидалось, что ${issue.origin} будет ${adj}${issue.minimum.toString()}`;
+    }
+    case "invalid_format": {
+      const _issue = issue as errors.$ZodStringFormatIssues;
+      if (_issue.format === "starts_with") return `Неверная строка: должна начинаться с "${_issue.prefix}"`;
+      if (_issue.format === "ends_with") return `Неверная строка: должна заканчиваться на "${_issue.suffix}"`;
+      if (_issue.format === "includes") return `Неверная строка: должна содержать "${_issue.includes}"`;
+      if (_issue.format === "regex") return `Неверная строка: должна соответствовать шаблону ${_issue.pattern}`;
+      return `Неверный ${Nouns[_issue.format] ?? issue.format}`;
+    }
+    case "not_multiple_of":
+      return `Неверное число: должно быть кратным ${issue.divisor}`;
+    case "unrecognized_keys":
+      return `Нераспознанн${issue.keys.length > 1 ? "ые" : "ый"} ключ${issue.keys.length > 1 ? "и" : ""}: ${util.joinValues(issue.keys, ", ")}`;
+    case "invalid_key":
+      return `Неверный ключ в ${issue.origin}`;
+    case "invalid_union":
+      return "Неверные входные данные";
+    case "invalid_element":
+      return `Неверное значение в ${issue.origin}`;
+    default:
+      return `Неверные входные данные`;
+  }
+};
+
+export { error };
+
+export default function (): { localeError: errors.$ZodErrorMap } {
+  return {
+    localeError: error,
+  };
+}
diff --git a/packages/core/tests/locales/ru.test.ts b/packages/core/tests/locales/ru.test.ts
new file mode 100644
index 0000000000..8abe6d7276
--- /dev/null
+++ b/packages/core/tests/locales/ru.test.ts
@@ -0,0 +1,128 @@
+import { describe, expect, it } from "vitest";
+import ru from "../../src/locales/ru.js";
+
+describe("Russian localization", () => {
+  const { localeError } = ru();
+
+  describe("pluralization rules", () => {
+    for (const { type, cases } of TEST_CASES) {
+      describe(`${type} pluralization`, () => {
+        for (const { count, expected } of cases) {
+          it(`correctly pluralizes ${count} ${type}`, () => {
+            const error = localeError({
+              code: "too_small",
+              minimum: count,
+              type: "number",
+              inclusive: true,
+              path: [],
+              origin: type,
+              input: count - 1,
+            });
+
+            expect(error).toContain(expected);
+          });
+        }
+      });
+    }
+
+    it("handles negative numbers correctly", () => {
+      const error = localeError({
+        code: "too_small",
+        minimum: -2,
+        type: "number",
+        inclusive: true,
+        path: [],
+        origin: "array",
+        input: -3,
+      });
+
+      expect(error).toContain("-2 элемента");
+    });
+
+    it("handles zero correctly", () => {
+      const error = localeError({
+        code: "too_small",
+        minimum: 0,
+        type: "number",
+        inclusive: true,
+        path: [],
+        origin: "array",
+        input: -1,
+      });
+
+      expect(error).toContain("0 элементов");
+    });
+
+    it("handles bigint values correctly", () => {
+      const error = localeError({
+        code: "too_small",
+        minimum: BigInt(21),
+        type: "number",
+        inclusive: true,
+        path: [],
+        origin: "array",
+        input: BigInt(20),
+      });
+
+      expect(error).toContain("21 элемент");
+    });
+  });
+});
+
+const TEST_CASES = [
+  {
+    type: "array",
+    cases: [
+      { count: 1, expected: "1 элемент" },
+      { count: 2, expected: "2 элемента" },
+      { count: 5, expected: "5 элементов" },
+      { count: 11, expected: "11 элементов" },
+      { count: 21, expected: "21 элемент" },
+      { count: 22, expected: "22 элемента" },
+      { count: 25, expected: "25 элементов" },
+      { count: 101, expected: "101 элемент" },
+      { count: 111, expected: "111 элементов" },
+    ],
+  },
+  {
+    type: "set",
+    cases: [
+      { count: 1, expected: "1 элемент" },
+      { count: 2, expected: "2 элемента" },
+      { count: 5, expected: "5 элементов" },
+      { count: 11, expected: "11 элементов" },
+      { count: 21, expected: "21 элемент" },
+      { count: 22, expected: "22 элемента" },
+      { count: 25, expected: "25 элементов" },
+      { count: 101, expected: "101 элемент" },
+      { count: 111, expected: "111 элементов" },
+    ],
+  },
+  {
+    type: "string",
+    cases: [
+      { count: 1, expected: "1 символ" },
+      { count: 2, expected: "2 символа" },
+      { count: 5, expected: "5 символов" },
+      { count: 11, expected: "11 символов" },
+      { count: 21, expected: "21 символ" },
+      { count: 22, expected: "22 символа" },
+      { count: 25, expected: "25 символов" },
+    ],
+  },
+  {
+    type: "file",
+    cases: [
+      { count: 0, expected: "0 байт" },
+      { count: 1, expected: "1 байт" },
+      { count: 2, expected: "2 байта" },
+      { count: 5, expected: "5 байт" },
+      { count: 11, expected: "11 байт" },
+      { count: 21, expected: "21 байт" },
+      { count: 22, expected: "22 байта" },
+      { count: 25, expected: "25 байт" },
+      { count: 101, expected: "101 байт" },
+      { count: 110, expected: "110 байт" },
+    ],
+  },
+] as const;
diff --git a/packages/docs/content/error-customization.mdx b/packages/docs/content/error-customization.mdx
index 2e0cd2fe10..51b07247f0 100644
--- a/packages/docs/content/error-customization.mdx
+++ b/packages/docs/content/error-customization.mdx
@@ -358,6 +358,8 @@ The following locales are available:
 - `ar` — Arabic
 - `az` — Azerbaijani
 - `en` — English
+- `es` — Spanish
+- `ru` — Russian
 - `tr` — Türkçe
 - `it` — Italian
 - `cs` - Czech