diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -269,6 +269,7 @@
     libc.src.stdio.fwrite
     libc.src.stdio.fwrite_unlocked
     libc.src.stdio.sprintf
+    libc.src.stdio.snprintf
 
     # signal.h entrypoints
     # TODO: Enable signal.h entrypoints after fixing signal.h
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
--- a/libc/spec/stdc.td
+++ b/libc/spec/stdc.td
@@ -539,6 +539,27 @@
                ArgSpec<ConstCharRestrictedPtr>,
                ArgSpec<VarArgType>]
           >,
+          FunctionSpec<
+              "snprintf",
+              RetValSpec<IntType>,
+              [ArgSpec<CharRestrictedPtr>,
+               ArgSpec<SizeTType>,
+               ArgSpec<ConstCharRestrictedPtr>,
+               ArgSpec<VarArgType>]
+          >,
+          FunctionSpec<
+              "printf",
+              RetValSpec<IntType>,
+              [ArgSpec<ConstCharRestrictedPtr>,
+               ArgSpec<VarArgType>]
+          >,
+          FunctionSpec<
+              "fprintf",
+              RetValSpec<IntType>,
+              [ArgSpec<FILERestrictedPtr>,
+               ArgSpec<ConstCharRestrictedPtr>,
+               ArgSpec<VarArgType>]
+          >,
       ]
   >;
 
diff --git a/libc/src/stdio/CMakeLists.txt b/libc/src/stdio/CMakeLists.txt
--- a/libc/src/stdio/CMakeLists.txt
+++ b/libc/src/stdio/CMakeLists.txt
@@ -211,7 +211,18 @@
   HDRS
     sprintf.h
   DEPENDS
-    libc.include.stdio
+    libc.src.stdio.printf_core.printf_main
+    libc.src.stdio.printf_core.string_writer
+    libc.src.stdio.printf_core.writer
+)
+
+add_entrypoint_object(
+  snprintf
+  SRCS
+    snprintf.cpp
+  HDRS
+    snprintf.h
+  DEPENDS
     libc.src.stdio.printf_core.printf_main
     libc.src.stdio.printf_core.string_writer
     libc.src.stdio.printf_core.writer
diff --git a/libc/src/stdio/snprintf.h b/libc/src/stdio/snprintf.h
new file mode 100644
--- /dev/null
+++ b/libc/src/stdio/snprintf.h
@@ -0,0 +1,21 @@
+//===-- Implementation header of snprintf -----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_STDIO_SNPRINTF_H
+#define LLVM_LIBC_SRC_STDIO_SNPRINTF_H
+
+#include <stddef.h>
+
+namespace __llvm_libc {
+
+int snprintf(char *__restrict buffer, size_t buffsz,
+             const char *__restrict format, ...);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_STDIO_SNPRINTF_H
diff --git a/libc/src/stdio/sprintf.cpp b/libc/src/stdio/snprintf.cpp
copy from libc/src/stdio/sprintf.cpp
copy to libc/src/stdio/snprintf.cpp
--- a/libc/src/stdio/sprintf.cpp
+++ b/libc/src/stdio/snprintf.cpp
@@ -1,4 +1,4 @@
-//===-- Implementation of sprintf -------------------------------*- C++ -*-===//
+//===-- Implementation of snprintf ------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/stdio/sprintf.h"
+#include "src/stdio/snprintf.h"
 
 #include "src/__support/arg_list.h"
 #include "src/stdio/printf_core/printf_main.h"
@@ -14,24 +14,26 @@
 #include "src/stdio/printf_core/writer.h"
 
 #include <stdarg.h>
+#include <stddef.h>
 
 namespace __llvm_libc {
 
-LLVM_LIBC_FUNCTION(int, sprintf,
-                   (char *__restrict buffer, const char *__restrict format,
-                    ...)) {
+LLVM_LIBC_FUNCTION(int, snprintf,
+                   (char *__restrict buffer, size_t buffsz,
+                    const char *__restrict format, ...)) {
   va_list vlist;
   va_start(vlist, format);
   internal::ArgList args(vlist); // This holder class allows for easier copying
-                                 // and pointer semantics, as well as handing
+                                 // and pointer semantics, as well as handling
                                  // destruction automatically.
   va_end(vlist);
-  printf_core::StringWriter str_writer(buffer);
+  printf_core::StringWriter str_writer(buffer, (buffsz > 0 ? buffsz - 1 : 0));
   printf_core::Writer writer(reinterpret_cast<void *>(&str_writer),
                              printf_core::write_to_string);
 
   int ret_val = printf_core::printf_main(&writer, format, args);
-  str_writer.terminate();
+  if (buffsz > 0) // if the buffsz is 0 the buffer may be a null pointer.
+    str_writer.terminate();
   return ret_val;
 }
 
diff --git a/libc/src/stdio/sprintf.cpp b/libc/src/stdio/sprintf.cpp
--- a/libc/src/stdio/sprintf.cpp
+++ b/libc/src/stdio/sprintf.cpp
@@ -23,7 +23,7 @@
   va_list vlist;
   va_start(vlist, format);
   internal::ArgList args(vlist); // This holder class allows for easier copying
-                                 // and pointer semantics, as well as handing
+                                 // and pointer semantics, as well as handling
                                  // destruction automatically.
   va_end(vlist);
   printf_core::StringWriter str_writer(buffer);
diff --git a/libc/test/src/stdio/CMakeLists.txt b/libc/test/src/stdio/CMakeLists.txt
--- a/libc/test/src/stdio/CMakeLists.txt
+++ b/libc/test/src/stdio/CMakeLists.txt
@@ -73,6 +73,16 @@
     libc.src.stdio.sprintf
 )
 
+add_libc_unittest(
+  snprintf_test
+  SUITE
+    libc_stdio_unittests
+  SRCS
+    snprintf_test.cpp
+  DEPENDS
+    libc.src.stdio.snprintf
+)
+
 add_subdirectory(printf_core)
 
 add_subdirectory(testdata)
diff --git a/libc/test/src/stdio/snprintf_test.cpp b/libc/test/src/stdio/snprintf_test.cpp
new file mode 100644
--- /dev/null
+++ b/libc/test/src/stdio/snprintf_test.cpp
@@ -0,0 +1,46 @@
+//===-- Unittests for snprintf --------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdio/snprintf.h"
+
+#include "utils/UnitTest/Test.h"
+
+// The sprintf test cases cover testing the shared printf functionality, so
+// these tests will focus on snprintf exclusive features.
+
+TEST(LlvmLibcSNPrintfTest, CutOff) {
+  char buff[64];
+  int written;
+
+  written =
+      __llvm_libc::snprintf(buff, 16, "A simple string with no conversions.");
+  EXPECT_EQ(written, 36);
+  ASSERT_STREQ(buff, "A simple string");
+
+  written = __llvm_libc::snprintf(buff, 5, "%s", "1234567890");
+  EXPECT_EQ(written, 10);
+  ASSERT_STREQ(buff, "1234");
+
+  // passing null as the output pointer is allowed as long as buffsz is 0.
+  written = __llvm_libc::snprintf(nullptr, 0, "%s and more", "1234567890");
+  EXPECT_EQ(written, 19);
+}
+
+TEST(LlvmLibcSNPrintfTest, NoCutOff) {
+  char buff[64];
+  int written;
+
+  written =
+      __llvm_libc::snprintf(buff, 37, "A simple string with no conversions.");
+  EXPECT_EQ(written, 36);
+  ASSERT_STREQ(buff, "A simple string with no conversions.");
+
+  written = __llvm_libc::snprintf(buff, 20, "%s", "1234567890");
+  EXPECT_EQ(written, 10);
+  ASSERT_STREQ(buff, "1234567890");
+}