diff --git a/README.md b/README.md
index 53368dd49..579cf590e 100644
--- a/README.md
+++ b/README.md
@@ -596,6 +596,7 @@ z.string().uuid();
 z.string().cuid();
 z.string().cuid2();
 z.string().regex(regex);
+z.string().includes(string);
 z.string().startsWith(string);
 z.string().endsWith(string);
 z.string().trim(); // trim whitespace
@@ -626,6 +627,7 @@ z.string().email({ message: "Invalid email address" });
 z.string().url({ message: "Invalid url" });
 z.string().emoji({ message: "Contains non-emoji characters" });
 z.string().uuid({ message: "Invalid UUID" });
+z.string().includes("tuna", { message: "Must include tuna" });
 z.string().startsWith("https://", { message: "Must provide secure URL" });
 z.string().endsWith(".com", { message: "Only .com domains allowed" });
 z.string().datetime({ message: "Invalid datetime string! Must be UTC." });
diff --git a/deno/lib/README.md b/deno/lib/README.md
index 439cfecd2..373816052 100644
--- a/deno/lib/README.md
+++ b/deno/lib/README.md
@@ -594,6 +594,7 @@ z.string().uuid();
 z.string().cuid();
 z.string().cuid2();
 z.string().regex(regex);
+z.string().includes(string);
 z.string().startsWith(string);
 z.string().endsWith(string);
 z.string().trim(); // trim whitespace
@@ -624,6 +625,7 @@ z.string().email({ message: "Invalid email address" });
 z.string().url({ message: "Invalid url" });
 z.string().emoji({ message: "Contains non-emoji characters" });
 z.string().uuid({ message: "Invalid UUID" });
+z.string().includes("tuna", { message: "Must include tuna" });
 z.string().startsWith("https://", { message: "Must provide secure URL" });
 z.string().endsWith(".com", { message: "Only .com domains allowed" });
 z.string().datetime({ message: "Invalid datetime string! Must be UTC." });
diff --git a/deno/lib/ZodError.ts b/deno/lib/ZodError.ts
index def27ddfc..c1b9c6fc0 100644
--- a/deno/lib/ZodError.ts
+++ b/deno/lib/ZodError.ts
@@ -98,6 +98,7 @@ export type StringValidation =
   | "cuid2"
   | "datetime"
   | "ip"
+  | { includes: string; position?: number }
   | { startsWith: string }
   | { endsWith: string };
 
diff --git a/deno/lib/__tests__/string.test.ts b/deno/lib/__tests__/string.test.ts
index 4e1e5a5bb..f76d98479 100644
--- a/deno/lib/__tests__/string.test.ts
+++ b/deno/lib/__tests__/string.test.ts
@@ -7,7 +7,9 @@ import * as z from "../index.ts";
 const minFive = z.string().min(5, "min5");
 const maxFive = z.string().max(5, "max5");
 const justFive = z.string().length(5);
-const nonempty = z.string().nonempty("nonempty");
+const nonempty = z.string().min(1, "nonempty");
+const includes = z.string().includes("includes");
+const includesFromIndex2 = z.string().includes("includes", { position: 2 });
 const startsWith = z.string().startsWith("startsWith");
 const endsWith = z.string().endsWith("endsWith");
 
@@ -18,6 +20,8 @@ test("passing validations", () => {
   maxFive.parse("1234");
   nonempty.parse("1");
   justFive.parse("12345");
+  includes.parse("XincludesXX");
+  includesFromIndex2.parse("XXXincludesXX");
   startsWith.parse("startsWithX");
   endsWith.parse("XendsWith");
 });
@@ -28,6 +32,8 @@ test("failing validations", () => {
   expect(() => nonempty.parse("")).toThrow();
   expect(() => justFive.parse("1234")).toThrow();
   expect(() => justFive.parse("123456")).toThrow();
+  expect(() => includes.parse("XincludeXX")).toThrow();
+  expect(() => includesFromIndex2.parse("XincludesXX")).toThrow();
   expect(() => startsWith.parse("x")).toThrow();
   expect(() => endsWith.parse("x")).toThrow();
 });
diff --git a/deno/lib/locales/en.ts b/deno/lib/locales/en.ts
index 30e564ce0..0665af275 100644
--- a/deno/lib/locales/en.ts
+++ b/deno/lib/locales/en.ts
@@ -47,7 +47,13 @@ const errorMap: ZodErrorMap = (issue, _ctx) => {
       break;
     case ZodIssueCode.invalid_string:
       if (typeof issue.validation === "object") {
-        if ("startsWith" in issue.validation) {
+        if ("includes" in issue.validation) {
+          message = `Invalid input: must include "${issue.validation.includes}"`;
+
+          if (typeof issue.validation.position === "number") {
+            message = `${message} at one or more positions greater than or equal to ${issue.validation.position}`;
+          }
+        } else if ("startsWith" in issue.validation) {
           message = `Invalid input: must start with "${issue.validation.startsWith}"`;
         } else if ("endsWith" in issue.validation) {
           message = `Invalid input: must end with "${issue.validation.endsWith}"`;
diff --git a/deno/lib/types.ts b/deno/lib/types.ts
index da20a76c0..23d8f14e0 100644
--- a/deno/lib/types.ts
+++ b/deno/lib/types.ts
@@ -496,6 +496,7 @@ export type ZodStringCheck =
   | { kind: "emoji"; message?: string }
   | { kind: "uuid"; message?: string }
   | { kind: "cuid"; message?: string }
+  | { kind: "includes"; value: string; position?: number; message?: string }
   | { kind: "cuid2"; message?: string }
   | { kind: "startsWith"; value: string; message?: string }
   | { kind: "endsWith"; value: string; message?: string }
@@ -736,6 +737,16 @@ export class ZodString extends ZodType<string, ZodStringDef> {
         }
       } else if (check.kind === "trim") {
         input.data = input.data.trim();
+      } else if (check.kind === "includes") {
+        if (!(input.data as string).includes(check.value, check.position)) {
+          ctx = this._getOrReturnCtx(input, ctx);
+          addIssueToContext(ctx, {
+            code: ZodIssueCode.invalid_string,
+            validation: { includes: check.value, position: check.position },
+            message: check.message,
+          });
+          status.dirty();
+        }
       } else if (check.kind === "toLowerCase") {
         input.data = input.data.toLowerCase();
       } else if (check.kind === "toUpperCase") {
@@ -865,6 +876,15 @@ export class ZodString extends ZodType<string, ZodStringDef> {
     });
   }
 
+  includes(value: string, options?: { message?: string; position?: number }) {
+    return this._addCheck({
+      kind: "includes",
+      value: value,
+      position: options?.position,
+      ...errorUtil.errToObj(options?.message),
+    });
+  }
+
   startsWith(value: string, message?: errorUtil.ErrMessage) {
     return this._addCheck({
       kind: "startsWith",
diff --git a/src/ZodError.ts b/src/ZodError.ts
index 0802c1793..f76acb10c 100644
--- a/src/ZodError.ts
+++ b/src/ZodError.ts
@@ -98,6 +98,7 @@ export type StringValidation =
   | "cuid2"
   | "datetime"
   | "ip"
+  | { includes: string; position?: number }
   | { startsWith: string }
   | { endsWith: string };
 
diff --git a/src/__tests__/string.test.ts b/src/__tests__/string.test.ts
index fa55796ca..132c9a9fa 100644
--- a/src/__tests__/string.test.ts
+++ b/src/__tests__/string.test.ts
@@ -6,7 +6,9 @@ import * as z from "../index";
 const minFive = z.string().min(5, "min5");
 const maxFive = z.string().max(5, "max5");
 const justFive = z.string().length(5);
-const nonempty = z.string().nonempty("nonempty");
+const nonempty = z.string().min(1, "nonempty");
+const includes = z.string().includes("includes");
+const includesFromIndex2 = z.string().includes("includes", { position: 2 });
 const startsWith = z.string().startsWith("startsWith");
 const endsWith = z.string().endsWith("endsWith");
 
@@ -17,6 +19,8 @@ test("passing validations", () => {
   maxFive.parse("1234");
   nonempty.parse("1");
   justFive.parse("12345");
+  includes.parse("XincludesXX");
+  includesFromIndex2.parse("XXXincludesXX");
   startsWith.parse("startsWithX");
   endsWith.parse("XendsWith");
 });
@@ -27,6 +31,8 @@ test("failing validations", () => {
   expect(() => nonempty.parse("")).toThrow();
   expect(() => justFive.parse("1234")).toThrow();
   expect(() => justFive.parse("123456")).toThrow();
+  expect(() => includes.parse("XincludeXX")).toThrow();
+  expect(() => includesFromIndex2.parse("XincludesXX")).toThrow();
   expect(() => startsWith.parse("x")).toThrow();
   expect(() => endsWith.parse("x")).toThrow();
 });
diff --git a/src/locales/en.ts b/src/locales/en.ts
index f09f48735..11325a95b 100644
--- a/src/locales/en.ts
+++ b/src/locales/en.ts
@@ -47,7 +47,13 @@ const errorMap: ZodErrorMap = (issue, _ctx) => {
       break;
     case ZodIssueCode.invalid_string:
       if (typeof issue.validation === "object") {
-        if ("startsWith" in issue.validation) {
+        if ("includes" in issue.validation) {
+          message = `Invalid input: must include "${issue.validation.includes}"`;
+
+          if (typeof issue.validation.position === "number") {
+            message = `${message} at one or more positions greater than or equal to ${issue.validation.position}`;
+          }
+        } else if ("startsWith" in issue.validation) {
           message = `Invalid input: must start with "${issue.validation.startsWith}"`;
         } else if ("endsWith" in issue.validation) {
           message = `Invalid input: must end with "${issue.validation.endsWith}"`;
diff --git a/src/types.ts b/src/types.ts
index cd01a65e3..4b0051ee3 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -496,6 +496,7 @@ export type ZodStringCheck =
   | { kind: "emoji"; message?: string }
   | { kind: "uuid"; message?: string }
   | { kind: "cuid"; message?: string }
+  | { kind: "includes"; value: string; position?: number; message?: string }
   | { kind: "cuid2"; message?: string }
   | { kind: "startsWith"; value: string; message?: string }
   | { kind: "endsWith"; value: string; message?: string }
@@ -736,6 +737,16 @@ export class ZodString extends ZodType<string, ZodStringDef> {
         }
       } else if (check.kind === "trim") {
         input.data = input.data.trim();
+      } else if (check.kind === "includes") {
+        if (!(input.data as string).includes(check.value, check.position)) {
+          ctx = this._getOrReturnCtx(input, ctx);
+          addIssueToContext(ctx, {
+            code: ZodIssueCode.invalid_string,
+            validation: { includes: check.value, position: check.position },
+            message: check.message,
+          });
+          status.dirty();
+        }
       } else if (check.kind === "toLowerCase") {
         input.data = input.data.toLowerCase();
       } else if (check.kind === "toUpperCase") {
@@ -865,6 +876,15 @@ export class ZodString extends ZodType<string, ZodStringDef> {
     });
   }
 
+  includes(value: string, options?: { message?: string; position?: number }) {
+    return this._addCheck({
+      kind: "includes",
+      value: value,
+      position: options?.position,
+      ...errorUtil.errToObj(options?.message),
+    });
+  }
+
   startsWith(value: string, message?: errorUtil.ErrMessage) {
     return this._addCheck({
       kind: "startsWith",