diff --git a/storm/String.cpp b/storm/String.cpp
index 0cf003e..0b732f0 100644
--- a/storm/String.cpp
+++ b/storm/String.cpp
@@ -498,6 +498,38 @@ const char* SStrStr(const char* string, const char* search) {
     return nullptr;
 }
 
+char* SStrStrI(char* string, const char* search) {
+    STORM_VALIDATE_BEGIN;
+    STORM_VALIDATE(string);
+    STORM_VALIDATE(search);
+    STORM_VALIDATE_END;
+
+    size_t searchLength = SStrLen(search);
+
+    for (; *string; string++) {
+        if (!SStrCmpI(string, search, searchLength)) {
+            return string;
+        }
+    }
+    return nullptr;
+}
+
+const char* SStrStrI(const char* string, const char* search) {
+    STORM_VALIDATE_BEGIN;
+    STORM_VALIDATE(string);
+    STORM_VALIDATE(search);
+    STORM_VALIDATE_END;
+
+    size_t searchLength = SStrLen(search);
+
+    for (; *string; string++) {
+        if (!SStrCmpI(string, search, searchLength)) {
+            return string;
+        }
+    }
+    return nullptr;
+}
+
 void SStrTokenize(const char** string, char* buffer, size_t bufferchars, const char* whitespace, int32_t* quoted) {
     STORM_VALIDATE_BEGIN;
     STORM_VALIDATE(string);
diff --git a/storm/String.hpp b/storm/String.hpp
index d489607..275d663 100644
--- a/storm/String.hpp
+++ b/storm/String.hpp
@@ -40,6 +40,10 @@ char* SStrStr(char* string, const char* search);
 
 const char* SStrStr(const char* string, const char* search);
 
+char* SStrStrI(char* string, const char* search);
+
+const char* SStrStrI(const char* string, const char* search);
+
 void SStrTokenize(const char** string, char* buffer, size_t bufferchars, const char* whitespace, int32_t* quoted);
 
 double SStrToDouble(const char* string);
diff --git a/test/String.cpp b/test/String.cpp
index 16c8b7e..574b322 100644
--- a/test/String.cpp
+++ b/test/String.cpp
@@ -440,6 +440,11 @@ TEST_CASE("SStrStr", "[string]") {
 
     static_assert(std::is_same<decltype(SStrStr(string, "")), char*>::value, "Expect result to be char*");
 
+    SECTION("is case sensitive") {
+        char* substring = SStrStr(string, "OOBA");
+        REQUIRE(substring == nullptr);
+    }
+
     SECTION("finds substring when it exists at end of string") {
         char* substring = SStrStr(string, "bar");
         REQUIRE(substring == string + 3);
@@ -472,6 +477,11 @@ TEST_CASE("SStrStr const", "[string]") {
 
     static_assert(std::is_same<decltype(SStrStr(string, "")), const char*>::value, "Expect result to be const char*");
 
+    SECTION("is case sensitive") {
+        const char* substring = SStrStr(string, "OOBA");
+        REQUIRE(substring == nullptr);
+    }
+
     SECTION("finds substring when it exists at end of string") {
         const char* substring = SStrStr(string, "bar");
         REQUIRE(substring == string + 3);
@@ -498,6 +508,79 @@ TEST_CASE("SStrStr const", "[string]") {
     }
 }
 
+TEST_CASE("SStrStrI", "[string]") {
+    char* string = "foobar";
+
+    static_assert(std::is_same<decltype(SStrStrI(string, "")), char*>::value, "Expect result to be char*");
+
+    SECTION("is case insensitive") {
+        char* substring = SStrStrI(string, "OOBA");
+        REQUIRE(substring == string + 1);
+    }
+
+    SECTION("finds substring when it exists at end of string") {
+        char* substring = SStrStrI(string, "bar");
+        REQUIRE(substring == string + 3);
+    }
+
+    SECTION("finds substring when it exists at start of string") {
+        char* substring = SStrStrI(string, "foo");
+        REQUIRE(substring == string);
+    }
+
+    SECTION("finds substring when search is empty") {
+        char* substring = SStrStrI(string, "");
+        REQUIRE(substring == string);
+    }
+
+    SECTION("returns nullptr when search does not exist in string") {
+        char* substring = SStrStrI(string, "xyzzy");
+        REQUIRE(substring == nullptr);
+    }
+
+    SECTION("returns nullptr when given empty string") {
+        char* string = "";
+        char* substring = SStrStrI(string, "bar");
+        REQUIRE(substring == nullptr);
+    }
+}
+
+TEST_CASE("SStrStrI const", "[string]") {
+    const char* string = "foobar";
+
+    static_assert(std::is_same<decltype(SStrStrI(string, "")), const char*>::value, "Expect result to be const char*");
+
+    SECTION("is case insensitive") {
+        const char* substring = SStrStrI(string, "OOBA");
+        REQUIRE(substring == string + 1);
+    }
+
+    SECTION("finds substring when it exists at end of string") {
+        const char* substring = SStrStrI(string, "bar");
+        REQUIRE(substring == string + 3);
+    }
+
+    SECTION("finds substring when it exists at start of string") {
+        const char* substring = SStrStrI(string, "foo");
+        REQUIRE(substring == string);
+    }
+
+    SECTION("finds substring when search is empty") {
+        const char* substring = SStrStrI(string, "");
+        REQUIRE(substring == string);
+    }
+
+    SECTION("returns nullptr when search does not exist in string") {
+        const char* substring = SStrStrI(string, "xyzzy");
+        REQUIRE(substring == nullptr);
+    }
+
+    SECTION("returns nullptr when given empty string") {
+        const char* substring = SStrStrI("", "bar");
+        REQUIRE(substring == nullptr);
+    }
+}
+
 TEST_CASE("SStrTokenize", "[string]") {
     SECTION("finds all tokens in comma-delimited string") {
         auto string = "foo,bar,baz";