diff --git a/CMakeLists.txt b/CMakeLists.txt
index 22ef3dcaa71c7..b53eea5f9ae52 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -397,6 +397,19 @@ if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
 
   set(SWIFT_PRIMARY_VARIANT_SDK_default "LINUX")
   set(SWIFT_PRIMARY_VARIANT_ARCH_default "x86_64")
+elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "FreeBSD")
+  configure_sdk_unix(FREEBSD "FreeBSD" "freebsd" "freebsd" "x86_64" "x86_64-freebsd10")
+
+  set(CMAKE_EXECUTABLE_FORMAT "ELF")
+
+  set(SWIFT_HOST_VARIANT "freebsd" CACHE STRING
+      "Deployment OS for Swift host tools (the compiler) [freebsd].")
+
+  set(SWIFT_HOST_VARIANT_SDK "FREEBSD")
+  set(SWIFT_HOST_VARIANT_ARCH "x86_64")
+
+  set(SWIFT_PRIMARY_VARIANT_SDK_default "FREEBSD")
+  set(SWIFT_PRIMARY_VARIANT_ARCH_default "x86_64")
 elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "Darwin")
   # Set defaults.
 
diff --git a/cmake/modules/AddSwift.cmake b/cmake/modules/AddSwift.cmake
index 38df30a51872e..c523924b2935c 100644
--- a/cmake/modules/AddSwift.cmake
+++ b/cmake/modules/AddSwift.cmake
@@ -151,6 +151,8 @@ function(_add_variant_link_flags
 
   if("${sdk}" STREQUAL "LINUX")
     list(APPEND result "-lpthread" "-ldl")
+  elseif("${sdk}" STREQUAL "FREEBSD")
+    # No extra libraries required.
   else()
     list(APPEND result "-lobjc")
   endif()
diff --git a/include/swift/Basic/LangOptions.h b/include/swift/Basic/LangOptions.h
index 66dae000800ad..d7bdd65dea672 100644
--- a/include/swift/Basic/LangOptions.h
+++ b/include/swift/Basic/LangOptions.h
@@ -173,7 +173,9 @@ namespace swift {
         Target.getiOSVersion(major, minor, revision);
       } else if (Target.isWatchOS()) {
         Target.getOSVersion(major, minor, revision);
-      } else if (Target.isOSLinux() || Target.getTriple().empty()) {
+      } else if (Target.isOSLinux() || Target.isOSFreeBSD() ||
+                 Target.getTriple().empty())
+      {
         major = minor = revision = 0;
       } else {
         llvm_unreachable("Unsupported target OS");
diff --git a/lib/Basic/LangOptions.cpp b/lib/Basic/LangOptions.cpp
index 4ad980cbb4e40..ae8c69d125368 100644
--- a/lib/Basic/LangOptions.cpp
+++ b/lib/Basic/LangOptions.cpp
@@ -28,7 +28,8 @@ const std::vector<std::string> LangOptions::SupportedOSBuildConfigArguments = {
   "tvOS",
   "watchOS",
   "iOS",
-  "Linux"
+  "Linux",
+  "FreeBSD"
 };
 
 const std::vector<std::string> LangOptions::SupportedArchBuildConfigArguments = {
@@ -98,6 +99,8 @@ std::pair<bool, bool> LangOptions::setTarget(llvm::Triple triple) {
     addTargetConfigOption("os", "iOS");
   else if (triple.isOSLinux())
     addTargetConfigOption("os", "Linux");
+  else if (triple.isOSFreeBSD())
+    addTargetConfigOption("os", "FreeBSD");
   else {
     UnsupportedOS = true;
   }
diff --git a/lib/Basic/Platform.cpp b/lib/Basic/Platform.cpp
index a4808d1db918b..a620f9e9e13af 100644
--- a/lib/Basic/Platform.cpp
+++ b/lib/Basic/Platform.cpp
@@ -64,5 +64,8 @@ StringRef swift::getPlatformNameForTriple(const llvm::Triple &triple) {
   if (triple.isOSLinux())
     return "linux";
 
+  if (triple.isOSFreeBSD())
+    return "freebsd";
+
   return "";
 }
diff --git a/lib/Driver/CMakeLists.txt b/lib/Driver/CMakeLists.txt
index 10e1de08f7a57..2bc7e9b785986 100644
--- a/lib/Driver/CMakeLists.txt
+++ b/lib/Driver/CMakeLists.txt
@@ -12,6 +12,8 @@ set(swiftDriver_sources
   Types.cpp
   )
 
+set(swiftDriver_targetDefines)
+
 add_swift_library(swiftDriver
   ${swiftDriver_sources}
   DEPENDS SwiftOptions
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 7dfe5ee6b8789..25601072edcf2 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -2036,7 +2036,10 @@ const ToolChain *Driver::getToolChain(const ArgList &Args) const {
       TC = new toolchains::Darwin(*this, Target);
       break;
     case llvm::Triple::Linux:
-      TC = new toolchains::Linux(*this, Target);
+      TC = new toolchains::GenericUnix(*this, Target);
+      break;
+    case llvm::Triple::FreeBSD:
+      TC = new toolchains::GenericUnix(*this, Target);
       break;
     default:
       TC = nullptr;
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index f6e9faa78126f..829e68293cbb3 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -999,8 +999,8 @@ toolchains::Darwin::constructInvocation(const LinkJobAction &job,
 }
 
 ToolChain::InvocationInfo
-toolchains::Linux::constructInvocation(const InterpretJobAction &job,
-                                       const JobContext &context) const {
+toolchains::GenericUnix::constructInvocation(const InterpretJobAction &job,
+                                             const JobContext &context) const {
   InvocationInfo II = ToolChain::constructInvocation(job, context);
 
   SmallString<128> runtimeLibraryPath;
@@ -1014,8 +1014,8 @@ toolchains::Linux::constructInvocation(const InterpretJobAction &job,
 
 
 ToolChain::InvocationInfo
-toolchains::Linux::constructInvocation(const AutolinkExtractJobAction &job,
-                                       const JobContext &context) const {
+toolchains::GenericUnix::constructInvocation(const AutolinkExtractJobAction &job,
+                                             const JobContext &context) const {
   assert(context.Output.getPrimaryOutputType() == types::TY_AutolinkFile);
 
   ArgStringList Arguments;
@@ -1030,8 +1030,8 @@ toolchains::Linux::constructInvocation(const AutolinkExtractJobAction &job,
 }
 
 ToolChain::InvocationInfo
-toolchains::Linux::constructInvocation(const LinkJobAction &job,
-                                       const JobContext &context) const {
+toolchains::GenericUnix::constructInvocation(const LinkJobAction &job,
+                                             const JobContext &context) const {
   const Driver &D = getDriver();
 
   assert(context.Output.getPrimaryOutputType() == types::TY_Image &&
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index dcda776468b83..7bc32e8f48452 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -36,7 +36,7 @@ class LLVM_LIBRARY_VISIBILITY Darwin : public ToolChain {
 
 };
 
-class LLVM_LIBRARY_VISIBILITY Linux : public ToolChain {
+class LLVM_LIBRARY_VISIBILITY GenericUnix : public ToolChain {
 protected:
   InvocationInfo constructInvocation(const InterpretJobAction &job,
                                      const JobContext &context) const override;
@@ -46,8 +46,8 @@ class LLVM_LIBRARY_VISIBILITY Linux : public ToolChain {
                                      const JobContext &context) const override;
 
 public:
-  Linux(const Driver &D, const llvm::Triple &Triple) : ToolChain(D, Triple) {}
-  ~Linux() = default;
+  GenericUnix(const Driver &D, const llvm::Triple &Triple) : ToolChain(D, Triple) {}
+  ~GenericUnix() = default;
 };
 
 } // end namespace toolchains
@@ -55,3 +55,4 @@ class LLVM_LIBRARY_VISIBILITY Linux : public ToolChain {
 } // end namespace swift
 
 #endif
+
diff --git a/stdlib/public/core/CMakeLists.txt b/stdlib/public/core/CMakeLists.txt
index 456857aa39413..5e44d5c14e69c 100644
--- a/stdlib/public/core/CMakeLists.txt
+++ b/stdlib/public/core/CMakeLists.txt
@@ -154,9 +154,13 @@ else()
   #  -Wl,--whole-archive swiftRuntime -Wl,--no-whole-archive)
   list(APPEND swift_core_private_link_libraries swiftRuntime swiftStdlibStubs)
   find_package(ICU REQUIRED COMPONENTS uc i18n)
+  list(APPEND swift_core_private_link_libraries
+      ${ICU_UC_LIBRARY} ${ICU_I18N_LIBRARY})
+endif()
+
+if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
   find_package(BSD REQUIRED)
   list(APPEND swift_core_private_link_libraries
-      ${ICU_UC_LIBRARY} ${ICU_I18N_LIBRARY}
       ${BSD_LIBRARIES})
 endif()
 
diff --git a/stdlib/public/runtime/CMakeLists.txt b/stdlib/public/runtime/CMakeLists.txt
index 2decd7e230050..c3fbdc7614359 100644
--- a/stdlib/public/runtime/CMakeLists.txt
+++ b/stdlib/public/runtime/CMakeLists.txt
@@ -72,7 +72,7 @@ add_swift_library(swiftRuntime IS_STDLIB IS_STDLIB_CORE
   INSTALL_IN_COMPONENT stdlib)
 
 foreach(sdk ${SWIFT_CONFIGURED_SDKS})
-  if("${sdk}" STREQUAL "LINUX")
+  if("${sdk}" STREQUAL "LINUX" OR "${sdk}" STREQUAL "FREEBSD")
     foreach(arch ${SWIFT_SDK_${sdk}_ARCHITECTURES})
       set(arch_subdir "${SWIFT_SDK_${sdk}_LIB_SUBDIR}/${arch}")
 
diff --git a/stdlib/public/runtime/Casting.cpp b/stdlib/public/runtime/Casting.cpp
index 34666e29110e8..48ea259ef21ca 100644
--- a/stdlib/public/runtime/Casting.cpp
+++ b/stdlib/public/runtime/Casting.cpp
@@ -2271,7 +2271,7 @@ namespace {
 #  if __APPLE__
       assert((!Success && Data <= 0xFFFFFFFFU) ||
              (Success && Data > 0xFFFFFFFFU));
-#  elif __linux__
+#  elif __linux__ || __FreeBSD__
       assert((!Success && Data <= 0x0FFFU) ||
              (Success && Data > 0x0FFFU));
 #  else
@@ -2306,7 +2306,7 @@ namespace {
 #if __LP64__
 #  if __APPLE__
       return Data > 0xFFFFFFFFU;
-#  elif __linux__
+#  elif __linux__ || __FreeBSD__
       return Data > 0x0FFFU;
 #  else
 #    error "port me"
diff --git a/stdlib/public/stubs/LibcShims.cpp b/stdlib/public/stubs/LibcShims.cpp
index b29fd6507247d..13d9d74a9f9fc 100644
--- a/stdlib/public/stubs/LibcShims.cpp
+++ b/stdlib/public/stubs/LibcShims.cpp
@@ -55,6 +55,11 @@ size_t _swift_stdlib_malloc_size(const void *ptr) { return malloc_size(ptr); }
 size_t _swift_stdlib_malloc_size(const void *ptr) {
   return malloc_usable_size(const_cast<void *>(ptr));
 }
+#elif defined(__FreeBSD__)
+#include <malloc_np.h>
+size_t _swift_stdlib_malloc_size(const void *ptr) {
+  return malloc_usable_size(const_cast<void *>(ptr));
+}
 #else
 #error No malloc_size analog known for this platform/libc.
 #endif
diff --git a/stdlib/public/stubs/Stubs.cpp b/stdlib/public/stubs/Stubs.cpp
index c1307fd12ee17..336f352010707 100644
--- a/stdlib/public/stubs/Stubs.cpp
+++ b/stdlib/public/stubs/Stubs.cpp
@@ -16,10 +16,15 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if defined(__FreeBSD__)
+#define _WITH_GETLINE
+#endif
+
 #include <sys/resource.h>
 #include <sys/errno.h>
 #include <unistd.h>
 #include <climits>
+#include <cstdarg>
 #include <cstdint>
 #include <cstdio>
 #include <cstdlib>
diff --git a/test/BuildConfigurations/x64FreeBSDTarget.swift b/test/BuildConfigurations/x64FreeBSDTarget.swift
new file mode 100644
index 0000000000000..284060fa6eb49
--- /dev/null
+++ b/test/BuildConfigurations/x64FreeBSDTarget.swift
@@ -0,0 +1,8 @@
+// RUN: %swift -parse %s -verify -D FOO -D BAR -target x86_64-unknown-freebsd10 -disable-objc-interop -D FOO -parse-stdlib
+// RUN: %swift-ide-test -test-input-complete -source-filename=%s -target x86_64-unknown-freebsd10
+
+#if arch(x86_64) && os(FreeBSD) && _runtime(_Native)
+class C {}
+var x = C()
+#endif
+var y = x
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index d5b74f0470da7..6bc8ed31d26ab 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -56,7 +56,8 @@ function(get_test_dependencies SDK result_var_name)
      ("${SDK}" STREQUAL "IOS_SIMULATOR") OR
      ("${SDK}" STREQUAL "TVOS_SIMULATOR") OR
      ("${SDK}" STREQUAL "WATCHOS_SIMULATOR") OR
-     ("${SDK}" STREQUAL "LINUX"))
+     ("${SDK}" STREQUAL "LINUX") OR
+     ("${SDK}" STREQUAL "FREEBSD"))
     # No extra dependencies.
   else()
     message(FATAL_ERROR "Unknown SDK: ${SDK}")